Object: Scramble the balls, then get them back to originial positions.
Or: Get the balls into one of the starting positions of the other variants.
 
Click a ball in the top half of a ring to rotate the ring clockwise.
Clicking a ball in the lower half of a ring turns the ring anticlockwise.
 
 
More freeware as well as real puzzles and games under http://karl.kiwi.gen.nz.