The goal of this puzzle is to visit all 20 cells exactly once, moving like the Chess Night. Hit the last cell to undo. Although this puzzle may seem extremely difficult, it is solvable. There are several solutions, even when you ignore the symmetrical ones. At this moment, hints are not implemented. Therefore, you may find it easier to first solve this puzzle on paper.
From the main menu, hit "New Game" to start game.
In the game, tap a cell on the touchscreen to paint it orange.
Tap on one of the white cells to hop to a legal destination.
Tap on the last cell (dark orange) to undo last move.
Hit the back key to end game and return to main menu.
Undo. Stalemate detection. Completion detection.