Art and music are really nice. I like how you turned the mechanic of being a bubble and shooting reduces your size to make puzzles. A lot of other people did something similar, but you did a good job of setting yours apart by making really cool puzzles. I couldn't figure out how to get to the next area at first, and then I couldn't figure out how to collect the key. It would have been nice if there was some text explaining how to do it.