Undo/Redo a Move

You can undo any number of moves during the game. To undo a move, press the Z key or select Undo from the menu on the right. When you undo a move, computer shows the latest move that was made before the moves that were undone. Please note that when you undo a move, both the computer's latest move and your latest move are undone.
You can redo any move you have undone. To redo a move, press the Y key or select Redo from the menu on the right. When you redo a move, both your and the computer's moves are redone.