You need to fill a 9x9 grid with digits so that each column, each row, and each of the nine 3x3 sub-grids that compose the grid contains all of the digits from 1 to 9 to win the game. Sudoku Features: - Six difficulties (very easy, easy, medium, hard, very Hard and Extreme) - Notes - Highlight incorrect values and duplicates -Three beautiful grid styles - Unlimited Undo/Redo - Player Statistics - Works great on tablet