1. The game has 20 levels, each lasting 5 seconds
2. Starting from 1 digit, increasing to 20 digits
3. Memorize the number and input it after the timer ends
4. Green indicator for correct answers, red for wrong
5. Points per level: Level 1 = 5pts, Level 2 = 10pts, etc.
6. Total possible score: 1050 points (Excellent: 840+)