Colored balls are falling down and you have to catch them with the side of the square that has the same color as those balls. You can rotate the square by touching either sides of the screen. Just pay attention to the balls color and the four colors of the square so that you can quickly and correctly rotate the square so that balls fall into the side of the square with the same color. You will lose if you fail to do so and your final score is based on the number of balls that you have collected.
Touch on mobile device or mouse on PC