A colored brick at the top of the screen fills up with color in a clockwise direction. Meanwhile you must try to place it to fall on bricks of the same color below. Once the brick is completely filled, it drops down automatically.
If the brick falls on or next to a brick of the same color, a chain reaction eliminates all connected bricks of that color. The objective of the game is to clear all bricks on each level using as few falling bricks as possible.