[Visual] Establish Distinct Visual Identity & Art Direction (VIS-ID-1)

[niyazmft]

Description

Context:
Emberfall currently lacks a cohesive visual identity. The 12×12 grid, elemental combos, and Moral Weight system are strong gameplay hooks, but the Steam store page and screenshots must communicate "this is not another generic tactics game" within 3 seconds.

Problem Statement:
Genre research shows players prioritize readability over beauty, but they also need a compelling reason to click. Games like Into the Breach and Metal Slug Tactics succeed because their art style is instantly recognizable. Emberfall risks being lost in the ~1,500+ annual tactical roguelike releases without a distinct visual signature.

Technical Rationale:
Visual identity is not just "nice art" — it is a marketing asset. A readable, distinct style reduces the cognitive load of grid comprehension and makes screenshots shareable.

Functional Requirements

• FR1: Define a core visual thesis in a VISUAL_IDENTITY.md doc: color palette (max 6 base colors + elemental accent colors), silhouette language (how Fire/Oil/Wind/Water look on grid), and UI chrome style.
  • File: docs/VISUAL_IDENTITY.md
• FR2: Design a readable grid tileset where: elevation = height shading, cover = outline thickness, combo-ready tiles = subtle pulse animation.
• FR3: Create enemy/player sprite sheets with silhouette-first design — must be identifiable at 32×32 px.
• FR4: Implement a "Screenshot Mode" (F12) that hides UI chrome and captures grid at 4K for store/marketing use.
• FR5: Ensure Deuteranopia-safe (EPT) color palette passes WCAG 2.1 AA contrast for all elemental states.

Acceptance Criteria (DoD)

• VISUAL_IDENTITY.md approved and committed to docs/.
• Grid is readable at 1080p without zooming; tile distinctions visible to colorblind players (verified via EPT shader).
• All characters identifiable by silhouette alone in a lineup test.
• "Screenshot Mode" produces PNG files in user://screenshots/.
• CI passes: no regressions in existing gut tests.

Edge Cases

Given	When	Then
Player has Deuteranopia enabled	Elemental colors shown	EPT shader remaps Fire→bright yellow, Water→cyan, etc.
Screenshot taken during animation	Frame is mid-fx	Mode pauses game, hides UI, renders clean frame
Grid zoomed to minimum	Sprites shrink below 32px	Pixel-art crispness maintained (no blurry filtering)