The rules are simple and easy to learn, but as it is the case with most puzzle games, you need a little time to really understand and master it. Object of the game is to fill the 9x9 grid with numbers. Each column, row and 3x3 block can contain the numbers 1 to 9 only once. And that’s all there is to know, really. The difficulty however is to find out, which row and which column misses which exact numbers in what place. Sounds complicated, but it’s all based on logic and a little brain teasing. Select your level of difficulty and choose between two input options for a comfortable game experience. All grids are generated randomly for basically unlimited hours of fun!