God I hate puzzle games like this but this one is so well done I have to give credit where credit is due. This is brain-bendingly difficult. How the hell did someone come up with this? I really like how there's a significant difference in difficulty between a star completion and a normal completion. The gameplay is simple yet clever and varied, and has the potential for both skill and strategy-based gameplay. The graphics and sound are simple but don't need to be complicated. What little physics do exist in the game are coded well.
I really can't think of anything that this game needs. Possibly more of a plot, different themes, or a better soundtrack. Other than that this is really amazing.