Great puzzle! Most of the game I was in one of the following states: What is going on here? Is this physically possible? I did it!, and then what?.. And only the stated limitations of the game (3x3 map, what could be easier?!) kept me from giving up when I once again got lost/broken the level/went around the map in a circle and still didn't understand anything.
The visual style and sound are also at a high level.
Only the lazy didn't tell you about physics. Didn't tell you, and I won't.
The only improvement that can be made right now is to change the screenshots. You can use them to make hints for all the mechanics. And make them understandable not only in animation but also in a freeze frame (as in the second screenshot).