Bring the mouse to the desired ball and press the left hey of the mouse. A marker meaning that the ball is chosen appears above the ball. Press the keys "up, down, right, left and virtual wheels begin rotating at the direction pointed by the arrow.
The ball indicated by the mouse along the arrow. Another ball from the depth of the space appears, on its place. The third ball disappears in the depth of the screen.
The bails start moving only when the ball indicated by the mouse and the ball.
pointed by the arrow are of different coolers.