Playing the game
When selecting a cell, you can either use the keyboard arrows or use the mouse. And
for entering a digit in that cell, you have three choices:
- Use the keybord number buttons
- Use one of the number buttons below the board
- Right-click the cell and choose a digit from the menu-list that pops up
Removing a cell digit is done either by using the keyboard space bar, or by
right-clicking the cell and choosing 'X' from the popup-list.
The number buttons can also be very helpful in showing patterns. In ordinary play
mode when you mouse-over a number button, it will highlight all cells containing that
digit.
List mode
When
entering a digit that is already on the list, that digit will be
removed from the
list for that cell.
Exception: When there is only one digit left, it will be entered as
the value for that cell when you press it. When moving the mouse over the
digit
buttons in this mode, all cells where that digit is included in the list will be highlighted.
Below the puzzle you have a couple of buttons that are really helpful:

The
reduce buttons can offer you quite advanced help with the more
difficult puzzles. The following strategies are implemented:
- X-Wing strategy.
- Simple colouring chaining strategy.
- XY-Wing strategy.
- X-Cycles strategy.
- True-false chain strategy.
- Forced chain strategy.
- Swordfish strategy.

This button rebuilds the lists of possible digits in all cells.
Notes:
Right-clicking the background image will show it without any disturbing buttons or
boards.
In the statistics window you can also right-click the background to see it clean.