Two or more circles will appear in each level. Tap the center of a circle to create a ball at its top, which begins to orbit at a fixed speed. Tap and hold a ball to stop it in place. Note: If a circle is flashing, its ball cannot be stopped. To complete a level, balls must orbiting in every circle. Precise timing is required to have all the balls orbiting. After one ball is started, wait for it to make one complete orbit. When it reaches the top of its circle again, start another ball orbiting. If timed correctly, the balls will never touch. Note: This only works in levels with stationary circles. You can scrub balls to manually stop their rotation. Simply tap them again while they are rotating to scrub them. Do this if a collision is imminent.