Sudoku puzzle games - Greater Than, Consecutive, Odd/Even, Diagonal, Double, Triple, Butterfly, Flower, Windmill, Samurai. You can choose letters or colors instead of digits.
Board size can be from 4 to 20 (default size is 9). Every puzzle has unique solution. The right mouse button is used to draw pencil marks.
This program also contains editor and solver and it can create PDF file which has multiple sudoku per page.
Other features: show candidates, unlimited undo/redo, save position to file, high scores, hint.