Rules:
- There are 20 levels. Each level lasts 5 seconds.
- In each level, a random number will be shown. The number of digits starts from 1 and increases by 1 each level, up to 20 digits.
- Memorize the number within 5 seconds.
- After the countdown, enter the number you remember.
- Each correct answer gives you points: Level 1 gives 5 points, Level 2 gives 10 points, ..., Level 20 gives 100 points. Total: 1050 points.
- 20 boxes at the top show your progress: green for correct, red for incorrect.
- Score 840 or above to be considered Excellent!