Sudoku is a Sudoku variant. The rules: The game is played with nine squares
which are arranges in a 3×3 formation. Every square is also divided into nine
grids. The program fills numbers into some grids and the player has to add the
rest. In every square, vertical row and horizontal row every number of 1-9 has
to be there exactly one time.

This variant features overall 4000 puzzles, help functions for beginners, a
save feature, four difficulty levels and a print function so the player can
solve the puzzles without a computer.

As a bonus, it additionally includes the game Golden Sub.