Fix bugs.
HOW TO PLAY:
1、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.
2、By moving the square, when the lower layer creates space and is large enough to accommodate the length of the upper layer, the upper square will fall to the lower layer. If all 8 grids of a row are filled by the cube and there is no extra space, the row is eliminated.
3、When you move the square last time and the number of lines has reached 10 lines, game over.
