I will be sincere, the gameplay is very minimalistic and repetitive.
I think given the time-limit and all, the art is pretty good and polished. I do miss more fun game-mechanics, so with more time I'm sure you would have created more interesting mechanics, like something that can damage the player, or push the player down?
As for fitting the theme, you scaling upwards is the only element, and it's lacking a bit on that as well.
I think over-all though it's a decent game for the game jam, you should be happy with what you've made.