Click the green flag and position the mouse pointer on the bug in the center circle. Once all the circles are drawn, a gap will appear in each circle. The gaps will move in different directions and at different speeds. The goal is to reach the star in the lower-left corner. Don't touch the black lines; that means you lose!
The gaps are made by a sprite that is the same color as the background and follows the same radius used to draw the circle. The circles do not themselves move at all.