Game contains large number of puzzles divided into three folders: Easy, Medium, and Hard.
When you enter a wrong value, game will alert dublicated figure with red color in line, column, or region.
There are three ways to enter the values: Pop, Single Number, or Numpad. Possible to choose which you like. And possible suspension ways in which you do not like from the Settings page.
In order to help you get familiar with these modes there will be several hints displayed as you go through them. You can disable these hints in game settings.
There is special page for help.
Possible to add a folder of your own and and fill in with your own puzzles
To add a folder: folders page > select Add Folder menu > Enter new golder > Select Add puzzle Menu > you'll see puzzle editing page.