Many variants of Sudoku puzzle games - Odd/Even, Greater Than, Consecutive, Killer, Diagonal, Double, Triple, Butterfly, Flower, Windmill, Samurai. You can set the board size from 4 to 20 (standard size is 9). You can choose colors or letters instead of digits. Every puzzle has a unique solution. The right mouse button is used to draw pencil marks. This program also contains editor and solver and it can create a PDF file which has multiple sudoku per page.