Add timed action play

[flinx42]

• Only show each digit [0-9] once on the screen
  allows for more paths to get to the right digit, but also may make it longer to get to it)
• Shuffle the placement of those 10 digits every XX seconds (could be based on selectable hardness level)
• (optional) have a total play time of XX minutes, that then determines your final score

With this you might only go through the first 10-20 digits, but it be more fun

[jrhunger]

True, fun was not really a goal in the original concept, but i like this idea.