| • | Click on an empty square of the Sudoku board to select it. |
| • | Once a square is selected, the left, right, up, and down arrow keys may be used to select a different square. |
| • | Click on an element in the list or press a key from 1 to 9 to modify the value in the selected square. |
| • | To clear a value in a square, repeat the value that is in the selected square or click the empty square in the element list. |
| • | To mark a value as a 'guess', click on the selected square. Click again to unmark it. |
| • | Click the 'Edit Pencil Marks' checkbox or right click on a square to toggle the edit mode. (Pencil mark editing allows the player to enter potential values for the square without committing to a value.) |
| • | To clear a pencil mark value, repeat the value of the pencil mark in the selected square. |
| • | Once the Sudoku puzzle is solved, the player's score is incremented. |
