Sudoku is a logic-based, combinatorial number-placement puzzle game. The objective is to fill a 9×9 grid with digits so that each column, each row, and each of the nine 3×3 sub-grids that compose the grid contains all of the digits from 1 to 9. Unlimited Undo & Redo. Provides a playing data save and load. Supports Achievements and Leaderboards.