The pixel art is very cute.
I especially appreciate the long attack window (i.e time player attack can damage) because it reduces the chance for unfair deaths to contact damage.
A telegraph for the bats dash would be nice since there were multiple occasions where I would jump up to slap one only for it to instantly dash into and damage me.
Might also have been interesting to make Buller's melee attack have a longer charge up and make them dash to emphasise Buller's strength and make them a hazard you have to pay more attention to.
The constant screams (?) did get annoying quite quickly.
In a potential future version it might also be interesting to have enemies interact with each other, for example a porcupine standing near another porcupine will always shoot out of sync to make it more of a hazard as currently they tend to just shoot in a straight line on the floor at the same time which is easy to dodge.