Nice short game. Could be more fun if Ball was useful for something.
It's not a bad game, but need lots of fixes, like glitches with the tiles when moving or jumping, or the gun sfx that doesn't stop when you stop shooting. Maybe adding some extra levels and some useful function to Ball would make it more fun to play.
The boss fight was interesting. Not very hard but at least was fun to play.
Good work! Congratulations!