Guide the smaller circle through the fieldoflarger circles for as long as you can.

In easy mode the circle moves up and down only. Tappingthescreen will increases the maximum distance the circle will moveandalso reverse it's up/down direction.

In hard mode the circle moves in a spiral like motion.Tappingthe screen will increases the maximum distance the circlewill moveand also reverse it's clockwise / anti-clockwisedirection.