This game is the same as sudoku, except that there is an additional constraint that the numbers in the diagonals must not repeat. In this game there will be a grid of 9 x 9 squares, each small grid of 3 x 3 squares is further grouped in to small groups. The object of this game is to fill in the squares with numbers 1 - 9 in such a way that the numbers in each row or column or diagonal must not repeat, and also the numbers in each small group must not repeat. The faster you finish the puzzle, the higher the score. If you are stuck, you can press the hint button to get some hint, but you will suffer a time penalty.