Must use brain to finish all levels. It's easy to learn but very difficult to master. The job of each level is to guide a ball from a predetermined start point so that it touches all of the stars placed on the level. The ball and nearly all objects on the screen are affected by gravity. The first few levels are almost too easy, but as the difficulty increases you'll be thankful that you were able to practice the fundamentals of draw. As the game progresses, you'll have to use all sorts of theory to figure out a solution for each puzzle.