You probably already know and like the Sudoku. In this case, you're probably also looking for something different, slightly more difficult, but even enjoyable. Good news: you've come to the right place for that. They're proud to present you their new challenge : the Kuboku, which is a real 3D version of the Sudoku. Instead of playing in a 9x9 grid, the player (you) will try to fill in an 8x8x8 3D cube, following exactly the same rules as the Sudoku : each digit (1..9 for the Sudoku and 1..8 for the Kuboku) must appear once and only once in each line and in each small area, a small area being a 3x3 square for the Sudoku and a 2x2x2 cube for the Kuboku. An exciting new challenge !