When starting a new game, you have the following options to customize the new puzzle:

Mode:

Size: You can specify the size of the board. Available sizes might differ depending on other settings.

Perfect diagonals: When this option is checked, each diagonal will contain one of each digit as well.

Levels: Sets the level of difficulty. Obviously EASY is the easiest, GEEK is the hardest. Available difficulty levels might differ depending on other settings.