diff --git a/client/src/BattleRoom.lua b/client/src/BattleRoom.lua
index 9eb433cb5..03190c149 100644
--- a/client/src/BattleRoom.lua
+++ b/client/src/BattleRoom.lua
@@ -15,7 +15,7 @@ local GeneratorSource = require("common.engine.GeneratorSource")
 
 -- A Battle Room is a session of matches, keeping track of the room number, player settings, wins / losses etc
 ---@class BattleRoom : Signal
----@field mode GameMode
+---@field mode GameMode The game mode configuration defining rules, player count, and match settings for this battle room
 ---@field players Player[]
 ---@field spectators string[]
 ---@field spectating boolean
@@ -59,7 +59,8 @@ end)
 BattleRoom.states = { Setup = 1, MatchInProgress = 2 }
 
 function BattleRoom.createFromServerMessage(message)
-  local battleRoom = BattleRoom(message.gameMode)
+  local gameMode = GameModes.createFromServerData(message.gameMode)
+  local battleRoom = BattleRoom(gameMode)
 
   if message.spectate_request_granted then
     logger.debug("Joining a match as spectator")
@@ -108,19 +109,8 @@ function BattleRoom.createFromServerMessage(message)
         p = Player(player.name, player.publicId or -i, false)
       end
 
-      -- order is important here as setting style will indirectly also override levelData so it needs to be before updateSettings
-      if gameMode.style ~= GameModes.Styles.CHOOSE then
-        p:setStyle(gameMode.style)
-      else
-        if player.settings.levelData then
-          if player.settings.levelData.frameConstants.GARBAGE_HOVER then
-            p:setStyle(GameModes.Styles.MODERN)
-          else
-            p:setStyle(GameModes.Styles.CLASSIC)
-          end
-        end
-      end
-
+      -- updateSettings will set levelData which triggers levelDataChanged signal
+      -- which will automatically update style based on the levelData
       p:updateSettings(player.settings)
 
       if player.ratingInfo then
@@ -141,30 +131,33 @@ function BattleRoom.createFromServerMessage(message)
   return battleRoom
 end
 
-function BattleRoom.createLocalFromGameMode(gameMode, gameScene)
+-- Creates a local (offline) BattleRoom from a GameMode configuration.
+-- For single-player modes, uses the game's main local player. For multi-player modes,
+-- creates temporary local players that don't persist settings changes.
+---@param gameMode GameMode The game mode configuration defining rules and player count
+---@param gameScene table? Optional scene class to use for matches (defaults to mode's gameScene)
+---@param settingChangesUpdateConfig boolean? If true, setting changes update config (default: true). Only applies to single-player modes.
+---@return BattleRoom? battleRoom The created battle room, or nil if input configuration assignment fails
+function BattleRoom.createLocalFromGameMode(gameMode, gameScene, settingChangesUpdateConfig)
+  if settingChangesUpdateConfig == nil then
+    settingChangesUpdateConfig = true
+  end
+
   local battleRoom = BattleRoom(gameMode, gameScene)
 
-  if gameMode.playerCount == 1 then
+  if settingChangesUpdateConfig and gameMode.playerCount == 1 then
     -- always use the game client's local player
     battleRoom:addPlayer(GAME.localPlayer)
   else
     -- with more than 1 local player we can't be sure which player is the "real" regular user
     -- so make them both local players that don't update config settings
     for i = 1, gameMode.playerCount do
-      local player = Player.getLocalPlayer()
+      local player = Player.createLocalPlayerFromConfig()
       player.name = loc("player_n", i)
       battleRoom:addPlayer(player)
     end
   end
 
-  if gameMode.style ~= GameModes.Styles.CHOOSE then
-    for i, player in ipairs(battleRoom.players) do
-      if player.human then
-        battleRoom.players[i]:setStyle(gameMode.style)
-      end
-    end
-  end
-
   if battleRoom:assignInputConfigurations() then
     return battleRoom
   else
@@ -404,28 +397,6 @@ function BattleRoom:createScene(match)
   end
 end
 
--- sets the style of "level" presets the players select from
--- 1 = classic
--- 2 = modern
--- longterm we want to abandon the concept of "style" on the player / battleRoom level
--- just setting difficulty or level should set the levelData and done with it, style is a menu-only concept
--- there is no technical reason why someone on level 10 shouldn't be able to play against someone on Hard
--- for now it's a battleRoom wide setting and players have to match
-function BattleRoom:setStyle(styleChoice)
-  -- style could be configurable per play instead but let's not for now
-  if self.mode.style == GameModes.Styles.CHOOSE then
-    self.style = styleChoice
-    self.onStyleChanged(styleChoice)
-  else
-    error("Trying to set difficulty style in a game mode that doesn't support style selection")
-  end
-end
-
--- not player specific, so this gets a separate callback that can only be overwritten once
--- so the UI can update and load up the different controls for it
-function BattleRoom.onStyleChanged(style, player)
-end
-
 function BattleRoom:startLoadingNewAssets()
   if ModLoader.loading_mod == nil then
     for _, player in ipairs(self.players) do
diff --git a/client/src/ClientMatch.lua b/client/src/ClientMatch.lua
index 8fb72fa95..dc55b77bd 100644
--- a/client/src/ClientMatch.lua
+++ b/client/src/ClientMatch.lua
@@ -396,10 +396,10 @@ function ClientMatch:finalizeReplay()
           ---@cast player Player
           metadata.name = player.name
           metadata.publicId = player.publicId
-          if player.settings.style == GameModes.Styles.MODERN then
-            metadata.level = player.settings.level
-          else
-            metadata.difficulty = player.settings.difficulty
+          if stack.level then
+            metadata.level = stack.level
+          elseif stack.difficulty then
+            metadata.difficulty = stack.difficulty
           end
           metadata.analytics = player.stack.analytic.data
           ---@diagnostic disable-next-line: inject-field
diff --git a/client/src/Game.lua b/client/src/Game.lua
index 5ea3a22d6..36eeffb4f 100644
--- a/client/src/Game.lua
+++ b/client/src/Game.lua
@@ -11,6 +11,7 @@ require("client.src.mods.Theme")
 -- Not to be confused with "Match" which is the current battle / instance of the game.
 local consts = require("common.engine.consts")
 local GraphicsUtil = require("client.src.graphics.graphics_util")
+local LevelPresets = require("common.data.LevelPresets")
 local class = require("common.lib.class")
 local logger = require("common.lib.logger")
 local analytics = require("client.src.analytics")
@@ -257,7 +258,7 @@ end
 -- GAME.localPlayer is the standard player for battleRooms that don't get started from replays/spectate
 -- it basically represents the player that is operating the client (and thus binds to its configuration)
 function Game:initializeLocalPlayer()
-  self.localPlayer = Player.getLocalPlayer()
+  self.localPlayer = Player.createLocalPlayerFromConfig()
   self.localPlayer:connectSignal("selectedCharacterIdChanged", config, function(config, newId) config.character = newId end)
   self.localPlayer:connectSignal("selectedStageIdChanged", config, function(config, newId) config.stage = newId end)
   self.localPlayer:connectSignal("panelIdChanged", config, function(config, newId) config.panels = newId end)
@@ -266,11 +267,17 @@ function Game:initializeLocalPlayer()
   self.localPlayer:connectSignal("difficultyChanged", config, function(config, difficulty) config.endless_difficulty = difficulty end)
   self.localPlayer:connectSignal("levelChanged", config, function(config, level) config.level = level end)
   self.localPlayer:connectSignal("wantsRankedChanged", config, function(config, wantsRanked) config.ranked = wantsRanked end)
-  self.localPlayer:connectSignal("styleChanged", config, function(config, style)
-    if style == GameModes.Styles.CLASSIC then
-      config.endless_level = nil
-    else
-      config.endless_level = config.level
+
+  self.localPlayer:connectSignal("levelDataChanged", config, function(config, levelData, player)
+    local presetInfo = LevelPresets.getStyleAndPreset(levelData)
+    if presetInfo then
+      if presetInfo.style == GameModes.Styles.MODERN then
+        config.level = presetInfo.level
+        config.endless_level = presetInfo.level
+      else
+        config.endless_difficulty = presetInfo.difficulty
+        config.endless_level = nil
+      end
     end
   end)
 end
@@ -305,21 +312,6 @@ function Game:createDirectoriesIfNeeded()
   end
 end
 
-function Game:runUnitTests()
-  coroutine.yield("Running Unit Tests")
-
-  -- GAME.localPlayer is the standard player for battleRooms that don't get started from replays/spectate
-  -- basically the player that is operating the client
-  GAME.localPlayer = Player.getLocalPlayer()
-  -- we need to overwrite the local player as all replay related tests need a non-local player
-  GAME.localPlayer.isLocal = false
-
-  logger.info("Running Unit Tests...")
-  GAME.muteSound = true
-  --require("client.tests.Tests")
-  SoundController:applyConfigVolumes()
-end
-
 function Game:runPerformanceTests()
   coroutine.yield("Running Performance Tests")
   require("tests.StackReplayPerformanceTests")
diff --git a/client/src/Player.lua b/client/src/Player.lua
index a7711081d..375b5866e 100644
--- a/client/src/Player.lua
+++ b/client/src/Player.lua
@@ -107,12 +107,19 @@ function Player:createClientStack(engineStack)
     player = self,
   }
 
-  if self.settings.style == GameModes.Styles.MODERN then
-    args.level = self.settings.level
-  else
-    args.difficulty = self.settings.difficulty
+  local presetInfo = LevelPresets.getStyleAndPreset(self.settings.levelData)
+  if presetInfo then
+    if presetInfo.style == GameModes.Styles.MODERN then
+      if presetInfo.level then
+        args.level = self.settings.level
+      end
+    else
+      if presetInfo.difficulty then
+        args.difficulty = self.settings.difficulty
+      end
+    end
   end
-
+  
   self.stack = PlayerStack(args)
 
   return self.stack
@@ -144,7 +151,7 @@ end
 function Player:setLevelData(levelData)
   self.settings.levelData = levelData
   self:setSpeed(levelData.startingSpeed)
-  self:emitSignal("levelDataChanged", levelData)
+  self:emitSignal("levelDataChanged", levelData, self)
 end
 
 function Player:setSpeed(speed)
@@ -172,18 +179,11 @@ end
 -- sets the style of "level" presets the player selects from
 -- 1 = classic
 -- 2 = modern
--- longterm we want to abandon the concept of "style" on the player / battleRoom level
--- just setting difficulty or level should set the levelData and done with it, style is a menu-only concept
--- there is no technical reason why someone on level 10 shouldn't be able to play against someone on Hard
+-- style is a menu-only concept for UI display
+-- derived settings (levelData) should be updated by calling gameMode.updateLocalPlayersDerivedSettings
 function Player:setStyle(style)
   if style ~= self.settings.style then
     self.settings.style = style
-    if style == GameModes.Styles.MODERN then
-      self:setLevelData(LevelPresets.getModern(self.settings.level or config.level))
-    else
-      self:setLevelData(LevelPresets.getClassic(self.settings.difficulty or config.endless_difficulty))
-      self:setSpeed(self.settings.speed)
-    end
     self:emitSignal("styleChanged", style)
   end
 end
@@ -233,7 +233,7 @@ function Player:unrestrictInputs()
 end
 
 ---@return Player
-function Player.getLocalPlayer()
+function Player.createLocalPlayerFromConfig()
   local player = Player(config.name, -1, true)
 
   player:setDifficulty(config.endless_difficulty)
@@ -246,10 +246,8 @@ function Player.getLocalPlayer()
   player:setInputMethod(config.inputMethod)
   if config.endless_level then
     player:setStyle(GameModes.Styles.MODERN)
-    player:setLevelData(LevelPresets.getModern(player.settings.level))
   else
     player:setStyle(GameModes.Styles.CLASSIC)
-    player:setLevelData(LevelPresets.getClassic(player.settings.difficulty))
     player:setSpeed(config.endless_speed)
   end
 
@@ -325,16 +323,6 @@ function Player:updateSettings(settings)
   end
 
   if settings.levelData ~= nil then
-    if settings.level ~= nil then
-      if settings.levelData.frameConstants.GARBAGE_HOVER then
-        self:setStyle(GameModes.Styles.MODERN)
-        self:setLevel(settings.level)
-      elseif settings.level <= LevelPresets.classicPresetCount then
-        self:setStyle(GameModes.Styles.CLASSIC)
-        self:setDifficulty(settings.level)
-      end
-    end
-
     self:setLevelData(settings.levelData)
   end
 
diff --git a/client/src/network/NetClient.lua b/client/src/network/NetClient.lua
index 4bb83eab1..d785a431c 100644
--- a/client/src/network/NetClient.lua
+++ b/client/src/network/NetClient.lua
@@ -458,6 +458,7 @@ function NetClient:requestSpectate(roomNumber)
   end
 end
 
+---@param gameMode GameMode
 function NetClient:requestRoom(gameMode)
   if self:isConnected() then
     self.tcpClient:sendRequest(ClientMessages.sendRoomRequest(gameMode))
diff --git a/client/src/scenes/CharacterSelect.lua b/client/src/scenes/CharacterSelect.lua
index f41efaf34..8ceac0802 100644
--- a/client/src/scenes/CharacterSelect.lua
+++ b/client/src/scenes/CharacterSelect.lua
@@ -4,11 +4,11 @@ local class = require("common.lib.class")
 local logger = require("common.lib.logger")
 local tableUtils = require("common.lib.tableUtils")
 local GameModes = require("common.data.GameModes")
+local LevelPresets = require("common.data.LevelPresets")
 local Scene = require("client.src.scenes.Scene")
 local ui = require("client.src.ui")
 local GraphicsUtil = require("client.src.graphics.graphics_util")
 local Character = require("client.src.mods.Character")
-local LevelPresets = require("common.data.LevelPresets")
 
 -- The character select screen scene
 ---@class CharacterSelect : Scene
@@ -57,7 +57,47 @@ function CharacterSelect:load()
   self.ui.cursors = {}
   self.ui.characterIcons = {}
   self.ui.playerInfos = {}
+
   self:customLoad()
+
+  for _, player in ipairs(self.players) do
+    if player:isHuman() then
+      if player.isLocal then
+        self:initializeFromLocalPlayerSettings(player)
+      end
+      player:connectSignal("levelDataChanged", self, self.onLevelDataChanged)
+      self:onLevelDataChanged(player.settings.levelData, player)
+    end
+  end
+end
+
+function CharacterSelect:onLevelDataChanged(levelData, player)
+  local presetInfo = LevelPresets.getStyleAndPreset(levelData)
+
+  if not presetInfo then
+    -- Custom levelData, default to current settings
+    return
+  end
+
+  if presetInfo.style == GameModes.Styles.MODERN then
+    player:setStyle(GameModes.Styles.MODERN)
+    if presetInfo.level then
+      player:setLevel(presetInfo.level)
+    end
+  else
+    player:setStyle(GameModes.Styles.CLASSIC)
+    if presetInfo.difficulty then
+      player:setDifficulty(presetInfo.difficulty)
+    end
+  end
+
+  self:refresh()
+end
+
+function CharacterSelect:initializeFromLocalPlayerSettings(player)
+  player:setStyle(GameModes.Styles.MODERN)
+  player:setLevel(player.settings.level)
+  player:setLevelData(LevelPresets.getModern(player.settings.level))
 end
 
 ---@param player Player
@@ -893,7 +933,7 @@ function CharacterSelect:createSpeedSlider(player, height, min)
   return uiElement
 end
 
-function CharacterSelect:createDifficultyCarousel(player, height)
+function CharacterSelect:createDifficultyCarousel(player, height, getPresetFunc)
   local passengers = {
     { id = 1, uiElement = ui.Label({text = "easy", vAlign = "center", hAlign = "center"})},
     { id = 2, uiElement = ui.Label({text = "normal", vAlign = "center", hAlign = "center"})},
@@ -918,25 +958,16 @@ function CharacterSelect:createDifficultyCarousel(player, height)
     -- Just update on every passenger change
   end
 
-  local updateDifficultyData = function(difficultyID)
-    local levelData = LevelPresets.getClassic(difficultyID)
-    player:setDifficulty(difficultyID)
-    if self.battleRoom.mode.name == "endless" and difficultyID == 1 then
-      -- Endless easy uses 5 colors instead of 6
-      levelData:setColorCount(5)
-      -- and by extension also allows adjacent panels of the same colors
-      levelData:setAdjacentDenialFrequency(0)
-    end
-    player:setLevelData(levelData)
-  end
   difficultyCarousel.onPassengerUpdateCallback = function(carousel, selectedPassenger)
-    updateDifficultyData(selectedPassenger.id)
+    player:setDifficulty(selectedPassenger.id)
+    if getPresetFunc then
+      player:setLevelData(getPresetFunc(selectedPassenger.id))
+    end
     GAME.theme:playMoveSfx()
-    self:refresh()
   end
-  -- Note that this updates the player level data which could be wrong before because of the weird endless case
-  -- its probably fine for now, but ideally the model should be right when the battle room is created
-  updateDifficultyData(difficultyCarousel.selectedId)
+
+  -- to update the UI if code gets changed from the backend (e.g. network messages)
+  player:connectSignal("difficultyChanged", difficultyCarousel, difficultyCarousel.setPassengerById)
 
   return difficultyCarousel
 end
diff --git a/client/src/scenes/CharacterSelectVsSelf.lua b/client/src/scenes/CharacterSelectVsSelf.lua
index dda09e6e3..59a22c562 100644
--- a/client/src/scenes/CharacterSelectVsSelf.lua
+++ b/client/src/scenes/CharacterSelectVsSelf.lua
@@ -85,14 +85,13 @@ function CharacterSelectVsSelf:refresh()
   local level
   if self.battleRoom then
     level = self.battleRoom.players[1].settings.level
-  else
-    level = GAME.localPlayer.settings.level
+    self.lastScore = GAME.scores:lastVsScoreForLevel(level)
+    self.record = GAME.scores:recordVsScoreForLevel(level)
+    if self.ui.recordBox then
+      self.ui.recordBox:setLastResult(self.lastScore)
+      self.ui.recordBox:setRecord(self.record)
+    end
   end
-
-  self.lastScore = GAME.scores:lastVsScoreForLevel(level)
-  self.record = GAME.scores:recordVsScoreForLevel(level)
-  self.ui.recordBox:setLastResult(self.lastScore)
-  self.ui.recordBox:setRecord(self.record)
 end
 
 return CharacterSelectVsSelf
\ No newline at end of file
diff --git a/client/src/scenes/EndlessGame.lua b/client/src/scenes/EndlessGame.lua
index 655bf50d9..cd12d3dcf 100644
--- a/client/src/scenes/EndlessGame.lua
+++ b/client/src/scenes/EndlessGame.lua
@@ -16,7 +16,7 @@ function EndlessGame:customLoad()
 end
 
 function EndlessGame:onMatchEnded(match)
-  if match.players[1].settings.style == GameModes.Styles.CLASSIC then
+  if match.players[1].stack.difficulty then
     GAME.scores:saveEndlessScoreForLevel(match.players[1].stack.engine.score, match.players[1].stack.difficulty)
   end
 end
diff --git a/client/src/scenes/EndlessMenu.lua b/client/src/scenes/EndlessMenu.lua
index 626c9c600..92bd9d967 100644
--- a/client/src/scenes/EndlessMenu.lua
+++ b/client/src/scenes/EndlessMenu.lua
@@ -1,6 +1,7 @@
 local CharacterSelect = require("client.src.scenes.CharacterSelect")
 local class = require("common.lib.class")
 local GameModes = require("common.data.GameModes")
+local LevelPresets = require("common.data.LevelPresets")
 local ui = require("client.src.ui")
 
 -- Scene for the endless game setup menu
@@ -71,7 +72,7 @@ function EndlessMenu:loadUserInterface()
   })
   self.ui.difficultySelection:setTitle("difficulty")
 
-  local difficultyCarousel = self:createDifficultyCarousel(player, self.ui.grid.unitSize - self.ui.grid.unitMargin * 2 - self.ui.difficultySelection.height)
+  local difficultyCarousel = self:createDifficultyCarousel(player, self.ui.grid.unitSize - self.ui.grid.unitMargin * 2 - self.ui.difficultySelection.height, LevelPresets.getClassicEndless)
   self.ui.difficultySelection:addElement(difficultyCarousel, player)
 
   self.ui.levelSelection = ui.MultiPlayerSelectionWrapper({hFill = true, alignment = "top", hAlign = "center", vAlign = "top"})
@@ -79,25 +80,14 @@ function EndlessMenu:loadUserInterface()
   local levelSlider = self:createLevelSlider(player, 20, self.ui.grid.unitSize - self.ui.grid.unitMargin * 2 - self.ui.levelSelection.height)
   self.ui.levelSelection:addElement(levelSlider, player)
 
-  if player.settings.style == GameModes.Styles.MODERN then
-    self.ui.grid:createElementAt(6, 2, 3, 1, "levelSelection", self.ui.levelSelection, nil, true)
-  else
-    self.ui.grid:createElementAt(6, 2, 2, 1, "speedSelection", self.ui.speedSelection, nil, true)
-    self.ui.grid:createElementAt(8, 2, 1, 1, "difficultySelection", self.ui.difficultySelection, nil, true)
-  end
-
   styleSelector.onValueChange = function(boolSelector, value)
     GAME.theme:playValidationSfx()
-    self.ui.grid:removeElementsIn(6, 2, 3, 1)
     if value and player.settings.style ~= GameModes.Styles.MODERN then
-      player:setStyle(GameModes.Styles.MODERN)
-      self.ui.grid:createElementAt(6, 2, 3, 1, "levelSelection", self.ui.levelSelection, nil, true)
-      self.ui.recordBox:setVisibility(false)
+      -- Set levelData for modern style - this will trigger levelDataChanged signal which updates UI
+      player:setLevelData(LevelPresets.getModern(player.settings.level))
     elseif value == false and player.settings.style ~= GameModes.Styles.CLASSIC then
-      player:setStyle(GameModes.Styles.CLASSIC)
-      self.ui.grid:createElementAt(6, 2, 2, 1, "speedSelection", self.ui.speedSelection, nil, true)
-      self.ui.grid:createElementAt(8, 2, 1, 1, "difficultySelection", self.ui.difficultySelection, nil, true)
-      self.ui.recordBox:setVisibility(true)
+      -- Set levelData for classic endless style - this will trigger levelDataChanged signal which updates UI
+      player:setLevelData(LevelPresets.getClassicEndless(player.settings.difficulty))
     end
   end
 
@@ -124,19 +114,42 @@ function EndlessMenu:loadUserInterface()
   self.ui.cursors[1].raise2Callback = function()
     self.ui.characterGrid:turnPage(1)
   end
+
+  player:connectSignal("styleChanged", self, self.onStyleChanged)
+  self:onStyleChanged(player.settings.style, player)
+end
+
+function EndlessMenu:onStyleChanged(style, player)
+  if style == GameModes.Styles.MODERN then
+    self.ui.grid:removeElementsIn(6, 2, 3, 1)
+    self.ui.grid:createElementAt(6, 2, 3, 1, "levelSelection", self.ui.levelSelection, nil, true)
+    self.ui.recordBox:setVisibility(false)
+  else
+    self.ui.grid:removeElementsIn(6, 2, 3, 1)
+    self.ui.grid:createElementAt(6, 2, 2, 1, "speedSelection", self.ui.speedSelection, nil, true)
+    self.ui.grid:createElementAt(8, 2, 1, 1, "difficultySelection", self.ui.difficultySelection, nil, true)
+    self.ui.recordBox:setVisibility(true)
+  end
+end
+
+function EndlessMenu:initializeFromLocalPlayerSettings(player)
+  if player.settings.style == GameModes.Styles.MODERN then
+    player:setLevelData(LevelPresets.getModern(player.settings.level))
+  else
+    player:setLevelData(LevelPresets.getClassicEndless(player.settings.difficulty))
+  end
 end
 
 function EndlessMenu:refresh()
-  local difficulty
   if self.battleRoom then
-    difficulty = self.battleRoom.players[1].settings.difficulty
-  else
-    difficulty = GAME.localPlayer.settings.difficulty
+    local difficulty = self.battleRoom.players[1].settings.difficulty
+    self.lastScore = GAME.scores:lastEndlessForLevel(difficulty)
+    self.record = GAME.scores:recordEndlessForLevel(difficulty)
+    if self.ui.recordBox then
+      self.ui.recordBox:setLastResult(self.lastScore)
+      self.ui.recordBox:setRecord(self.record)
+    end
   end
-  self.lastScore = GAME.scores:lastEndlessForLevel(difficulty)
-  self.record = GAME.scores:recordEndlessForLevel(difficulty)
-  self.ui.recordBox:setLastResult(self.lastScore)
-  self.ui.recordBox:setRecord(self.record)
 end
 
 return EndlessMenu
\ No newline at end of file
diff --git a/client/src/scenes/ReplayBrowser.lua b/client/src/scenes/ReplayBrowser.lua
index 30d42ad3f..14f0c8d11 100644
--- a/client/src/scenes/ReplayBrowser.lua
+++ b/client/src/scenes/ReplayBrowser.lua
@@ -223,8 +223,10 @@ function ReplayBrowser:draw()
         if player.level then
           GraphicsUtil.print(loc("rp_browser_info_level", player.level), menu_x + offsetX, menu_y + 95)
         else
-          GraphicsUtil.print(loc("rp_browser_info_speed", stack.levelData.startingSpeed), menu_x + offsetX, menu_y + 95)
-          GraphicsUtil.print(loc("rp_browser_info_difficulty", player.difficulty), menu_x + offsetX, menu_y + 110)
+          if player.difficulty then
+            GraphicsUtil.print(loc("rp_browser_info_speed", stack.levelData.startingSpeed), menu_x + offsetX, menu_y + 95)
+            GraphicsUtil.print(loc("rp_browser_info_difficulty", player.difficulty), menu_x + offsetX, menu_y + 110)
+          end
         end
       else
         ---@cast player SimulatedStackMetadata
diff --git a/client/src/scenes/TimeAttackGame.lua b/client/src/scenes/TimeAttackGame.lua
index 504f77767..1fd7af4a8 100644
--- a/client/src/scenes/TimeAttackGame.lua
+++ b/client/src/scenes/TimeAttackGame.lua
@@ -16,7 +16,7 @@ function TimeAttackGame:customLoad()
 end
 
 function TimeAttackGame:onMatchEnded(match)
-  if match.players[1].settings.style == GameModes.Styles.CLASSIC then
+  if match.players[1].stack.difficulty then
     GAME.scores:saveTimeAttack1PScoreForLevel(match.players[1].stack.engine.score, match.players[1].stack.difficulty)
   end
 end
diff --git a/client/src/scenes/TimeAttackMenu.lua b/client/src/scenes/TimeAttackMenu.lua
index 75904d97a..1ab39f816 100644
--- a/client/src/scenes/TimeAttackMenu.lua
+++ b/client/src/scenes/TimeAttackMenu.lua
@@ -1,6 +1,7 @@
 local class = require("common.lib.class")
 local CharacterSelect = require("client.src.scenes.CharacterSelect")
 local GameModes = require("common.data.GameModes")
+local LevelPresets = require("common.data.LevelPresets")
 local ui = require("client.src.ui")
 
 -- Scene for the time attack game setup menu
@@ -70,7 +71,7 @@ function TimeAttackMenu:loadUserInterface()
   })
   self.ui.difficultySelection:setTitle("difficulty")
 
-  local difficultyCarousel = self:createDifficultyCarousel(player, self.ui.grid.unitSize - self.ui.grid.unitMargin * 2 - self.ui.difficultySelection.height)
+  local difficultyCarousel = self:createDifficultyCarousel(player, self.ui.grid.unitSize - self.ui.grid.unitMargin * 2 - self.ui.difficultySelection.height, LevelPresets.getClassic)
   self.ui.difficultySelection:addElement(difficultyCarousel, player)
 
   self.ui.levelSelection = ui.MultiPlayerSelectionWrapper({hFill = true, alignment = "top", hAlign = "center", vAlign = "top"})
@@ -78,25 +79,14 @@ function TimeAttackMenu:loadUserInterface()
   local levelSlider = self:createLevelSlider(player, 20, self.ui.grid.unitSize - self.ui.grid.unitMargin * 2 - self.ui.levelSelection.height)
   self.ui.levelSelection:addElement(levelSlider, player)
 
-  if player.settings.style == GameModes.Styles.MODERN then
-    self.ui.grid:createElementAt(6, 2, 3, 1, "levelSelection", self.ui.levelSelection, nil, true)
-  else
-    self.ui.grid:createElementAt(6, 2, 2, 1, "speedSelection", self.ui.speedSelection, nil, true)
-    self.ui.grid:createElementAt(8, 2, 1, 1, "difficultySelection", self.ui.difficultySelection, nil, true)
-  end
-
   styleSelector.onValueChange = function(boolSelector, value)
     GAME.theme:playValidationSfx()
-    self.ui.grid:removeElementsIn(6, 2, 3, 1)
     if value and player.settings.style ~= GameModes.Styles.MODERN then
-      player:setStyle(GameModes.Styles.MODERN)
-      self.ui.grid:createElementAt(6, 2, 3, 1, "levelSelection", self.ui.levelSelection, nil, true)
-      self.ui.recordBox:setVisibility(false)
+      -- Set levelData for modern style - this will trigger levelDataChanged signal which updates UI
+      player:setLevelData(LevelPresets.getModern(player.settings.level))
     elseif value == false and player.settings.style ~= GameModes.Styles.CLASSIC then
-      player:setStyle(GameModes.Styles.CLASSIC)
-      self.ui.grid:createElementAt(6, 2, 2, 1, "speedSelection", self.ui.speedSelection, nil, true)
-      self.ui.grid:createElementAt(8, 2, 1, 1, "difficultySelection", self.ui.difficultySelection, nil, true)
-      self.ui.recordBox:setVisibility(true)
+      -- Set levelData for classic style - this will trigger levelDataChanged signal which updates UI
+      player:setLevelData(LevelPresets.getClassic(player.settings.difficulty))
     end
   end
 
@@ -123,20 +113,42 @@ function TimeAttackMenu:loadUserInterface()
   self.ui.cursors[1].raise2Callback = function()
     self.ui.characterGrid:turnPage(1)
   end
+
+  player:connectSignal("styleChanged", self, self.onStyleChanged)
+  self:onStyleChanged(player.settings.style, player)
 end
 
-function TimeAttackMenu:refresh()
-  local difficulty
-  if self.battleRoom then
-    difficulty = self.battleRoom.players[1].settings.difficulty
+function TimeAttackMenu:onStyleChanged(style, player)
+  if style == GameModes.Styles.MODERN then
+    self.ui.grid:removeElementsIn(6, 2, 3, 1)
+    self.ui.grid:createElementAt(6, 2, 3, 1, "levelSelection", self.ui.levelSelection, nil, true)
+    self.ui.recordBox:setVisibility(false)
   else
-    difficulty = GAME.localPlayer.settings.difficulty
+    self.ui.grid:removeElementsIn(6, 2, 3, 1)
+    self.ui.grid:createElementAt(6, 2, 2, 1, "speedSelection", self.ui.speedSelection, nil, true)
+    self.ui.grid:createElementAt(8, 2, 1, 1, "difficultySelection", self.ui.difficultySelection, nil, true)
+    self.ui.recordBox:setVisibility(true)
   end
+end
 
-  self.lastScore = GAME.scores:lastTimeAttack1PForLevel(difficulty)
-  self.record = GAME.scores:recordTimeAttack1PForLevel(difficulty)
-  self.ui.recordBox:setLastResult(self.lastScore)
-  self.ui.recordBox:setRecord(self.record)
+function TimeAttackMenu:initializeFromLocalPlayerSettings(player)
+  if player.settings.style == GameModes.Styles.MODERN then
+    player:setLevelData(LevelPresets.getModern(player.settings.level))
+  else
+    player:setLevelData(LevelPresets.getClassic(player.settings.difficulty))
+  end
+end
+
+function TimeAttackMenu:refresh()
+  if self.battleRoom then
+    local difficulty = self.battleRoom.players[1].settings.difficulty
+    self.lastScore = GAME.scores:lastTimeAttack1PForLevel(difficulty)
+    self.record = GAME.scores:recordTimeAttack1PForLevel(difficulty)
+    if self.ui.recordBox then
+      self.ui.recordBox:setLastResult(self.lastScore)
+      self.ui.recordBox:setRecord(self.record)
+    end
+  end
 end
 
 return TimeAttackMenu
\ No newline at end of file
diff --git a/client/src/scenes/VsSelfGame.lua b/client/src/scenes/VsSelfGame.lua
index b638a7345..c61dba5f1 100644
--- a/client/src/scenes/VsSelfGame.lua
+++ b/client/src/scenes/VsSelfGame.lua
@@ -16,7 +16,9 @@ end
 
 function VsSelfGame:onMatchEnded(match)
   local P1 = match.players[1].stack
-  GAME.scores:saveVsSelfScoreForLevel(P1.analytic.data.sent_garbage_lines, P1.level)
+  if P1.level then
+    GAME.scores:saveVsSelfScoreForLevel(P1.analytic.data.sent_garbage_lines, P1.level)
+  end
 end
 
 return VsSelfGame
\ No newline at end of file
diff --git a/client/src/ui/Grid.lua b/client/src/ui/Grid.lua
index 8d1d1cbbd..2dfc7a2bf 100644
--- a/client/src/ui/Grid.lua
+++ b/client/src/ui/Grid.lua
@@ -91,8 +91,12 @@ function Grid:drawSelf()
   end
 end
 
--- removes all gridElements overlapping with the specified box
--- the box is top left anchored
+--- removes all gridElements overlapping with the specified box
+--- the box is top left anchored
+---@param x integer 
+---@param y integer 
+---@param width integer 
+---@param height integer 
 function Grid:removeElementsIn(x, y, width, height)
   height = height or 1
   width = width or 1
diff --git a/client/tests/PlayerSettingsTests.lua b/client/tests/PlayerSettingsTests.lua
new file mode 100644
index 000000000..680b0dfa7
--- /dev/null
+++ b/client/tests/PlayerSettingsTests.lua
@@ -0,0 +1,108 @@
+local Player = require("client.src.Player")
+local GameModes = require("common.data.GameModes")
+local LevelPresets = require("common.data.LevelPresets")
+local CharacterSelect = require("client.src.scenes.CharacterSelect")
+local BattleRoom = require("client.src.BattleRoom")
+
+local function testDifficultyCarouselShouldNotMutatePlayerOnCreation()
+
+  local player = Player("TestPlayer", 1, true)
+
+  local gameMode = GameModes.getPreset("ONE_PLAYER_ENDLESS")
+  local battleRoom = BattleRoom(gameMode)
+  battleRoom:addPlayer(player)
+
+  local characterSelect = CharacterSelect({battleRoom = battleRoom})
+  
+  local originalLevel = player.settings.level
+  local originalDifficulty = player.settings.difficulty
+  local originalStyle = player.settings.style
+  local originalGarbageHover = player.settings.levelData.frameConstants.GARBAGE_HOVER
+  local originalColorCount = player.settings.levelData.colors
+
+  local _ = characterSelect:createDifficultyCarousel(player, 100)
+
+  assert(player.settings.level == originalLevel, "createDifficultyCarousel should not change level, but changed from " .. originalLevel .. " to " .. player.settings.level)
+  assert(player.settings.difficulty == originalDifficulty, "createDifficultyCarousel should not change difficulty, but changed from " .. tostring(originalDifficulty) .. " to " .. tostring(player.settings.difficulty))
+  assert(player.settings.style == originalStyle, "createDifficultyCarousel should not change style, but changed from " .. originalStyle .. " to " .. player.settings.style)
+  assert(player.settings.levelData.frameConstants.GARBAGE_HOVER == originalGarbageHover, "createDifficultyCarousel should not change GARBAGE_HOVER, but changed from " .. tostring(originalGarbageHover) .. " to " .. tostring(player.settings.levelData.frameConstants.GARBAGE_HOVER))
+  assert(player.settings.levelData.colors == originalColorCount, "createDifficultyCarousel should not change color count, but changed from " .. originalColorCount .. " to " .. player.settings.levelData.colors)
+
+  battleRoom:shutdown()
+end
+
+testDifficultyCarouselShouldNotMutatePlayerOnCreation()
+
+local function testEndlessModeClassicDifficulty1SetsCorrectSettings()
+
+  local gameMode = GameModes.getPreset("ONE_PLAYER_ENDLESS")
+  local battleRoom = BattleRoom.createLocalFromGameMode(gameMode, nil, false)
+
+  assert(battleRoom ~= nil, "BattleRoom should be created successfully")
+  assert(#battleRoom.players == 1, "BattleRoom should have exactly 1 player")
+
+  local battleRoomPlayer = battleRoom.players[1]
+
+  battleRoomPlayer:setLevelData(LevelPresets.getClassicEndless(1))
+
+  assert(battleRoomPlayer.settings.levelData.colors == 5,
+    "Endless mode with classic difficulty 1 should have 5 colors, but got " ..
+    tostring(battleRoomPlayer.settings.levelData.colors))
+
+  assert(battleRoomPlayer.settings.levelData.adjacentDenialFrequency == 0,
+    "Endless mode with classic difficulty 1 should have adjacent denial frequency of 0, but got " ..
+    tostring(battleRoomPlayer.settings.levelData.adjacentDenialFrequency))
+
+  battleRoom:shutdown()
+end
+
+testEndlessModeClassicDifficulty1SetsCorrectSettings()
+
+local function testVsSelfChangesEndlessClassicSettingsToModern()
+  -- First create an endless battle room with classic difficulty 1
+  local gameMode = GameModes.getPreset("ONE_PLAYER_ENDLESS")
+  local endlessBattleRoom = BattleRoom.createLocalFromGameMode(gameMode, nil, false)
+
+  assert(endlessBattleRoom ~= nil, "Endless BattleRoom should be created successfully")
+
+  local endlessPlayer = endlessBattleRoom.players[1]
+
+  -- Set to classic difficulty 1 (simulating what happens in endless mode)
+  endlessPlayer:setLevelData(LevelPresets.getClassicEndless(1))
+
+  -- Verify endless settings
+  assert(endlessPlayer.settings.style == GameModes.Styles.CLASSIC,
+    "Player should have classic style before vs self")
+  assert(endlessPlayer.settings.levelData.colors == 5,
+    "Player should have 5 colors before vs self")
+  assert(endlessPlayer.settings.levelData.adjacentDenialFrequency == 0,
+    "Player should have adjacent denial frequency of 0 before vs self")
+
+  endlessBattleRoom:shutdown()
+
+  -- Now create a vs self battle room which should change settings to modern
+  local vsSelfGameMode = GameModes.getPreset("ONE_PLAYER_VS_SELF")
+  local vsSelfBattleRoom = BattleRoom.createLocalFromGameMode(vsSelfGameMode, nil, false)
+
+  assert(vsSelfBattleRoom ~= nil, "Vs self BattleRoom should be created successfully")
+
+  local vsSelfPlayer = vsSelfBattleRoom.players[1]
+  vsSelfPlayer:setLevelData(LevelPresets.getModern(10))
+
+  assert(vsSelfPlayer.settings.levelData.frameConstants.GARBAGE_HOVER ~= nil,
+    "Modern style should have GARBAGE_HOVER set")
+
+  -- Modern levels have 6 colors (not 5 like endless classic difficulty 1)
+  assert(vsSelfPlayer.settings.levelData.colors == 6,
+    "Vs self should change color count to 6 (modern default), but got " ..
+    tostring(vsSelfPlayer.settings.levelData.colors))
+
+  -- Modern levels have non-zero adjacent denial frequency
+  assert(vsSelfPlayer.settings.levelData.adjacentDenialFrequency > 0,
+    "Vs self should have adjacent denial frequency > 0 (modern default), but got " ..
+    tostring(vsSelfPlayer.settings.levelData.adjacentDenialFrequency))
+
+  vsSelfBattleRoom:shutdown()
+end
+
+testVsSelfChangesEndlessClassicSettingsToModern()
diff --git a/client/tests/StackGraphicsTests.lua b/client/tests/StackGraphicsTests.lua
index ddaa19a0d..09db7e0bc 100644
--- a/client/tests/StackGraphicsTests.lua
+++ b/client/tests/StackGraphicsTests.lua
@@ -26,7 +26,7 @@ local function createEndlessClientMatch(playerCount, theme)
     playerCount = 1
   end
   for i = 1, playerCount do
-    local player = Player.getLocalPlayer()
+    local player = Player.createLocalPlayerFromConfig()
     player.isLocal = false
     player:setLevel(10)
     player:setLevelData(LevelPresets.getModern(10))
diff --git a/common/data/GameModes.lua b/common/data/GameModes.lua
index 398ffbb77..2e4efbc70 100644
--- a/common/data/GameModes.lua
+++ b/common/data/GameModes.lua
@@ -1,3 +1,4 @@
+local class = require("common.lib.class")
 local MatchRules = require("common.data.MatchRules")
 local TIME_ATTACK_TIME = 120
 
@@ -13,6 +14,25 @@ local GameModes = {}
 ---@field gameScene string
 ---@field style Styles
 ---@field richPresenceLabel string?
+---@field updateLocalPlayersDerivedSettings function
+local GameMode = class(function(self, properties)
+  for key, value in pairs(properties) do
+    self[key] = value
+  end
+end)
+
+-- Returns a copy of the game mode data suitable for JSON serialization
+-- Removes all methods/functions from the copied data
+---@return table
+function GameMode:getGameModeJSONData()
+  local gameModeData = deepcpy(self)
+  for key, value in pairs(gameModeData) do
+    if type(value) == "function" then
+      gameModeData[key] = nil
+    end
+  end
+  return gameModeData
+end
 
 -- longterm we want to abandon the concept of "style" on the engine and room setup level
 -- the engine only cares about levelData, style is a menu-only concept
@@ -24,8 +44,7 @@ local Styles = { CHOOSE = 0, CLASSIC = 1, MODERN = 2}
 local StackInteractions = { NONE = 0, VERSUS = 1, SELF = 2, ATTACK_ENGINE = 3 }
 
 ---@type GameMode
-local OnePlayerVsSelf = {
-  style = Styles.MODERN,
+local OnePlayerVsSelf = GameMode({
   gameScene = "VsSelfGame",
   richPresenceLabel = "1p vs self", -- loc("mm_1_vs"),
   name = "vsSelf",
@@ -40,12 +59,12 @@ local OnePlayerVsSelf = {
     stackWinConditions = {},
     stackSetupModifications = {},
     doCountdown = true,
-  }
-}
+  },
+
+})
 
 ---@type GameMode
-local OnePlayerTimeAttack = {
-  style = Styles.CHOOSE,
+local OnePlayerTimeAttack = GameMode({
   gameScene = "TimeAttackGame",
   richPresenceLabel = "Time Attack", -- loc("mm_1_time"),
   name = "timeattack",
@@ -60,12 +79,12 @@ local OnePlayerTimeAttack = {
     stackWinConditions = {},
     stackSetupModifications = {},
     doCountdown = true,
-  }
-}
+  },
+
+})
 
 ---@type GameMode
-local OnePlayerEndless = {
-  style = Styles.CHOOSE,
+local OnePlayerEndless = GameMode({
   gameScene = "EndlessGame",
   richPresenceLabel = "Endless", -- loc("mm_1_endless"),
   name = "endless",
@@ -80,12 +99,12 @@ local OnePlayerEndless = {
     stackWinConditions = {},
     stackSetupModifications = {},
     doCountdown = true,
-  }
-}
+  },
+
+})
 
 ---@type GameMode
-local OnePlayerTraining = {
-  style = Styles.MODERN,
+local OnePlayerTraining = GameMode({
   gameScene = "GameBase",
   richPresenceLabel = "Training", -- loc("mm_1_training"),
   name = "training",
@@ -100,13 +119,13 @@ local OnePlayerTraining = {
     stackWinConditions = {},
     stackSetupModifications = {},
     doCountdown = true,
-  }
-}
+  },
+
+})
 
 ---@type GameMode
-local OnePlayerPuzzle = {
+local OnePlayerPuzzle = GameMode({
   -- flags for battleRoom to evaluate and in some cases offer UI for
-  style = Styles.MODERN,
   richPresenceLabel = "Puzzle", -- loc("mm_1_puzzle"),
   gameScene = "PuzzleGame",
   name = "puzzle",
@@ -124,12 +143,12 @@ local OnePlayerPuzzle = {
     -- these are extended based on the loaded puzzle
     stackSetupModifications = {},
     doCountdown = false,
-  }
-}
+  },
+
+})
 
 ---@type GameMode
-local OnePlayerChallenge = {
-  style = Styles.MODERN,
+local OnePlayerChallenge = GameMode({
   gameScene = "Game1pChallenge",
   richPresenceLabel = "Challenge Mode", -- loc("mm_1_challenge_mode"),
   name = "challenge",
@@ -144,12 +163,12 @@ local OnePlayerChallenge = {
     stackWinConditions = {},
     stackSetupModifications = {},
     doCountdown = true,
-  }
-}
+  },
+
+})
 
 ---@type GameMode
-local TwoPlayerVersus = {
-  style = Styles.MODERN,
+local TwoPlayerVersus = GameMode({
   gameScene = "GameBase",
   richPresenceLabel = "2p versus", -- loc("mm_2_vs"),
   name = "VS",
@@ -164,11 +183,11 @@ local TwoPlayerVersus = {
     stackWinConditions = {},
     stackSetupModifications = {},
     doCountdown = true
-  }
-}
+  },
+
+})
 ---@type GameMode
-local TwoPlayerTimeAttack = {
-  style = Styles.MODERN,
+local TwoPlayerTimeAttack = GameMode({
   gameScene = "TimeAttackGame",
   richPresenceLabel = "2p Time Attack", -- loc("mm_2_time"),
   name = "2p_timeattack",
@@ -182,8 +201,9 @@ local TwoPlayerTimeAttack = {
     stackWinConditions = {},
     stackSetupModifications = {},
     doCountdown = true,
-  }
-}
+  },
+
+})
 
 GameModes.Styles = Styles
 GameModes.StackInteractions = StackInteractions
@@ -213,4 +233,27 @@ function GameModes.getPreset(mode)
   return deepcpy(privateGameModes[mode])
 end
 
+-- Creates a GameMode from server message data by loading the preset and applying overrides
+---@param gameModeData table The game mode data from the server message
+---@return GameMode
+function GameModes.createFromServerData(gameModeData)
+  local preset = nil
+  for _, gameMode in pairs(privateGameModes) do
+    if gameMode.name == gameModeData.name then
+      preset = gameMode
+      break
+    end
+  end
+
+  assert(preset, "Unknown game mode name: " .. tostring(gameModeData.name))
+
+  local result = deepcpy(preset)
+
+  for key, value in pairs(gameModeData) do
+    result[key] = value
+  end
+
+  return result
+end
+
 return GameModes
diff --git a/common/data/LevelPresets.lua b/common/data/LevelPresets.lua
index fa49c68d8..380ac1aea 100644
--- a/common/data/LevelPresets.lua
+++ b/common/data/LevelPresets.lua
@@ -1,6 +1,7 @@
 -- this file documents presets for level data
 local LevelData = require("common.data.LevelData")
 local JsonSafePrecision = require("common.data.JsonSafePrecision")
+local GameModes = require("common.data.GameModes")
 
 ---@type LevelData[]
 local modern = {}
@@ -326,4 +327,71 @@ end
 
 LevelPresets.classicPresetCount = #classic
 
+---@type (table<number | string, LevelData>)
+local classicEndless = {}
+-- Deep copy from classic presets and modify only what's different for endless mode
+classicEndless[1] = deepcpy(classic[1])
+-- Endless easy uses 5 colors instead of 6
+classicEndless[1]:setColorCount(5)
+-- and allows adjacent panels of the same colors
+classicEndless[1]:setAdjacentDenialFrequency(0)
+classicEndless.easy = classicEndless[1]
+
+-- Normal, hard, and ex are identical to classic mode for endless
+classicEndless[2] = deepcpy(classic[2])
+classicEndless.normal = classicEndless[2]
+
+classicEndless[3] = deepcpy(classic[3])
+classicEndless.hard = classicEndless[3]
+
+classicEndless[4] = deepcpy(classic[4])
+classicEndless.ex = classicEndless[4]
+
+---@param difficulty number | string the difficulty expressed as index 1 2 3 4 or easy normal hard ex
+---@return LevelData # a deepcopy of the classic endless preset
+function LevelPresets.getClassicEndless(difficulty)
+  assert(classicEndless[difficulty], "trying to load inexistent difficulty preset" .. difficulty)
+  return deepcpy(classicEndless[difficulty])
+end
+
+LevelPresets.classicEndlessPresetCount = #classicEndless
+
+---@class PresetInfo
+---@field style Styles
+---@field level integer?
+---@field difficulty integer?
+---@field isEndless boolean?
+
+---@param levelData LevelData
+---@return PresetInfo? # style and preset information, or nil if levelData doesn't match any preset
+function LevelPresets.getStyleAndPreset(levelData)
+  if not levelData then
+    return nil
+  end
+
+  -- Check modern presets
+  for level = 1, #modern do
+    if LevelData.__eq(levelData, modern[level]) then
+      return {style = GameModes.Styles.MODERN, level = level, difficulty = nil, isEndless = false}
+    end
+  end
+
+  -- Check classicEndless presets
+  for difficulty = 1, #classicEndless do
+    if LevelData.__eq(levelData, classicEndless[difficulty]) then
+      return {style = GameModes.Styles.CLASSIC, level = nil, difficulty = difficulty, isEndless = true}
+    end
+  end
+
+  -- Check classic presets
+  for difficulty = 1, #classic do
+    if LevelData.__eq(levelData, classic[difficulty]) then
+      return {style = GameModes.Styles.CLASSIC, level = nil, difficulty = difficulty, isEndless = false}
+    end
+  end
+
+  -- Doesn't match any preset - return nil
+  return nil
+end
+
 return LevelPresets
\ No newline at end of file
diff --git a/common/engine/Health.lua b/common/engine/Health.lua
index 0d0ce4465..7728929e2 100644
--- a/common/engine/Health.lua
+++ b/common/engine/Health.lua
@@ -1,6 +1,7 @@
 local logger = require("common.lib.logger")
 local consts = require("common.engine.consts")
 local class = require("common.lib.class")
+local JsonSafePrecision = require("common.data.JsonSafePrecision")
 
 ---@class HealthSettings
 ---@field framesToppedOutToLose number Starting value of framesToppedOutToLose
@@ -24,7 +25,7 @@ local Health = class(
   function(self, framesToppedOutToLose, lineClearGPM, height, riseSpeed)
     self.framesToppedOutToLose = framesToppedOutToLose
     self.maxSecondsToppedOutToLose = framesToppedOutToLose
-    self.lineClearRate = lineClearGPM / 60
+    self.lineClearRate = JsonSafePrecision.toSafePrecision(lineClearGPM / 60)
     self.currentLines = 0
     self.height = height
     self.lastWasFourCombo = false
@@ -139,7 +140,7 @@ end
 function Health:getSettings()
   return {
     framesToppedOutToLose = self.maxSecondsToppedOutToLose,
-    lineClearGPM = self.lineClearRate * 60,
+    lineClearGPM = JsonSafePrecision.toSafePrecision(self.lineClearRate * 60),
     lineHeightToKill = self.height,
     riseSpeed = self.initialRiseSpeed
   }
diff --git a/common/lib/util.lua b/common/lib/util.lua
index 3801ccd03..78439b103 100644
--- a/common/lib/util.lua
+++ b/common/lib/util.lua
@@ -114,7 +114,9 @@ function real_deepcpy(tab)
   return setmetatable(ret, getmetatable(tab))
 end
 
--- copys the full variable deeply
+-- Creates a deep copy of a table, recursively copying all nested tables
+-- Preserves metatables and handles circular references
+-- If the input is not a table, returns it unchanged
 ---@generic T
 ---@param tab T
 ---@return T deepCopy
diff --git a/common/network/ClientProtocol.lua b/common/network/ClientProtocol.lua
index 3ed87bf98..5f8d72a98 100644
--- a/common/network/ClientProtocol.lua
+++ b/common/network/ClientProtocol.lua
@@ -134,11 +134,13 @@ function ClientMessages.sendTaunt(direction, index)
   }
 end
 
+---@param gameMode GameMode
 function ClientMessages.sendRoomRequest(gameMode)
+  local gameModeData = gameMode:getGameModeJSONData()
   local roomRequestMessage = {
     recipient = "server",
     type = "roomRequest",
-    content = { gameMode = gameMode }
+    content = { gameMode = gameModeData }
   }
   return {
     messageType = msgTypes.jsonMessage,
diff --git a/server/Game.lua b/server/Game.lua
index b585da5c6..28f67a583 100644
--- a/server/Game.lua
+++ b/server/Game.lua
@@ -77,6 +77,8 @@ function Game.createFromRoomState(room)
       metadata.level = player.level
     else
       -- TODO: https://github.com/panel-attack/panel-game/issues/602
+      -- Use this pattern when we are in this area again and testing server
+      -- local presetInfo = LevelPresets.getStyleAndPreset(levelData)
       metadata.difficulty = player.level
     end
 
diff --git a/server/Room.lua b/server/Room.lua
index 87cc1d177..e2455db70 100644
--- a/server/Room.lua
+++ b/server/Room.lua
@@ -21,7 +21,7 @@ local ServerGame = require("server.Game")
 ---@field ratings table[] ratings by player number
 ---@field matchCount integer
 ---@field game ServerGame?
----@field gameMode GameMode
+---@field gameMode table -- only the data portion of the game mode
 ---@field ranked boolean if the next match is anticipated to be ranked 
 ---@field rankedReasons string[]
 ---@overload fun(roomNumber: integer, players: ServerPlayer[], gameMode: GameMode, leaderboard: Leaderboard?): Room
@@ -29,7 +29,7 @@ local Room = class(
 ---@param self Room
 ---@param roomNumber integer
 ---@param players ServerPlayer[]
----@param gameMode GameMode
+---@param gameMode table -- only the data portion of the game mode
 ---@param leaderboard Leaderboard?
 function(self, roomNumber, players, gameMode, leaderboard)
   self.players = players
diff --git a/server/tests/ServerTests.lua b/server/tests/ServerTests.lua
index e830581ab..17ea93d2c 100644
--- a/server/tests/ServerTests.lua
+++ b/server/tests/ServerTests.lua
@@ -269,7 +269,7 @@ local function testSinglePlayer()
   assert(message.type == "spectatorUpdate")
   message = alice.connection.outgoingMessageQueue:pop().messageText
   assert(message.type == "spectateRequestGranted" and message.content.replay == nil)
-  assert(tableUtils.deep_content_equal(message.content.gameMode, GameModes.getPreset("ONE_PLAYER_VS_SELF")))
+  assert(tableUtils.deep_content_equal(message.content.gameMode, GameModes.getPreset("ONE_PLAYER_VS_SELF"):getGameModeJSONData()))
   message = alice.connection.outgoingMessageQueue:pop().messageText
   assert(message.type == "spectatorUpdate")
 
diff --git a/testLauncher.lua b/testLauncher.lua
index 119c52ef9..19393cec8 100644
--- a/testLauncher.lua
+++ b/testLauncher.lua
@@ -92,6 +92,7 @@ local allTests = {
   "client.tests.TcpClientTests",
   "client.tests.ThemeTests",
   "client.tests.StackGraphicsTests",
+  "client.tests.PlayerSettingsTests",
 }
 
 -- Check for specific test name argument