How to play:
- One computer, use the mouse to play.
- On mobile, touch the screen to play.
- Choose a level (easy, medium, hard) forward your ability to play.
- Your goal is to fulfill all blank in the board with the digits 1 through 9 along the condition: each horizontal, vertical lines and 3×3 box contains each number (from 1 to 9) exactly once.
- Players can click the number to see its location on the board. If you choose the wrong number, you will lose score.