Sudoku is a mathematical logic game composed of 9×9 grids. Players need to infer the numbers of other grids based on the numbers provided by the grid. Four difficulty levels (40, 36, 32, 28 numbers) are provided in the game so that there is only one answer to the puzzle. This kind of game only requires logical thinking skills, and has nothing to do with digital operations. Although the gameplay is simple, the numbers provided are ever-changing, so many educators think Sudoku is a good way to exercise their brains.

As a report by Om Johar, a former scientist at the Illinois Institute of Technology, Sudoku helps to activate the brain, develop endurance, relieve stress, resolve loneliness, and focus: *Activate the brain: even if it is only a beginning or intermediate level Independence, it has been very helpful to training the brain. If you insist on completing the high difficulty series, you lose the meaning of playing Sudoku and cannot achieve the relaxation effect. Johar suggested that you can try the difficult one once a week. If you can't do it, just leave it!

Features:
- Four difficulty levels
- Record the best break time
- Toggle locked text color in puzzle
- Toggle highlight color in puzzle
- One-click clear and replay
- Pause game
- Check & clear errors when filling up
- Write notes
- Get hints