Amazing entry. Playing felt like I was actively creating a diagram for a science text book. I love puzzle games that don't have a single set in stone solution, and this helped to scratch that itch. I didn't care much for the comets or reversed planets, but the game was solid and enjoyable out. The gimmick for the final level was perfect (even if I couldn't complete it). You constantly find yourself one magic pixel away from victory in this game, and I think it works to the games benefit. There's always a tense moment right as you let go of the mouse hoping that everything lasts just long enough for the win. The sfx did get a little grating after a while, but I somehow sunk an HOUR into this game and didn't even notice.
You've made something great here, be very proud!