When you start the game and enter the main interface. In an 8X10 checkerboard, 2-3 rows of squares are randomly raised from the bottom. You can only move one square in the horizontal direction at a time, and there is space next to the square to be moved.
When you accidentally move an error you can click the back button to go back to the previous step
When you accidentally move an error you can click the back button to go back to the previous step