is a challenging logic-based puzzle game. The goal of the game is to fill the cells of a nine by nine grid with the digits 1 through 9. One important rule must be followed: each row, column, and sub grid must contain only one instance of each number. The puzzle is solved when all of the cells have been correctly filled. Each time you play, you are faced with a completely new challenge - iSS Sudoku has an infinite number of puzzles, so no two games are ever the same!