To start a new game, press the menu button in the top-right corner of the window, and select New Game. If you are already playing a game, Hitori will ask if you want to stop the current game.

To paint a cell, click on it; to unpaint it again, click on it again. When cells are painted such that none of the three rules are broken, the game will end and the board may no longer be manipulated.

Hitori also allows you to tag cells for your own reference when solving a board. This can be achieved by holding Ctrl or Shift and clicking on a cell. They both tag cells differently, and cells can be tagged in both manners at the same time. Tagged cells can be un-tagged by clicking on them again while holding either Ctrl or Shift again.

To undo or redo a move, press Undo or Redo in the header bar. You may undo or redo as many moves as you like without restriction.

To get a hint on which cells to paint out, press Hint in the header bar. A cell will be hinted with a flashing red outline. This shows that the current status of the cell (painted or unpainted) is incorrect, and should be changed for the game to be won.