I think this would be a great arcade cabinet game! As it is, it's very short and sweet but the core gameplay of it is fun, art style is great.
It might be cool to , when toward the end of a level loop, have some kind of prestige/ascension system to where you will unlock newer abilities at scale before going up against a boss, to where the mechanics center around needing to grow during the boss phases by responding to events happening in that boss fight.
Well done overall!