Fill in the grid so every possible value appears exactly once in every group. The following variations are available:

• Classic Sudoku - Put each of the digits 1-9 in every row, column and 3x3 inner group.
• Sudoku Extra - Like classic sudoku but with 4 extra inner groups.
• Extreme - Put each of the digits 1-8 in every row, column, diagonal and both 4x2 and 2x4 inner groups.
• Squidgy - Put each of the digits 1-9 in every row, column and the 9 variously shaped inner groups.
• Mini - Put each of the digits 1-6 in every row, column, diagonal and 3x2 inner group.
• 12x12 - Put each of the digits 1-9 and letters A-C in every row, column, diagonal and 4x3 inner group.

1. Position the mouse pointer over the square you want to set. Click the left mouse button. From the popup window you can select the value - or a number of possible values - for the square.
2. Position the mouse pointer over the square you want to set. Press the appropriate key on your keyboard for the value you want to set the square to.