A ball is moving inside the square.Each side of the square has a specific color. The ball is also colored with one of these colors. All you have to do is to make sure that the ball wont hit the side with the same color and you can do this by touching the screen and changing the balls color. After each time that you change the balls color, it will also change the direction that it moves. You will lose if you fail to change the balls color correctly or if you change it when its not necessary.
Touch on mobile device or mouse on PC.