I like the atmosphere here a lot, and the slow souls-like combat is a cool idea in pico8. I only made it to the first boss, and he knocked me flat. I also only got to him by avoiding combat and running away from everyone - the bats are really very hard to beat without taking a hit.
Maybe add a reward for fighting? A small health drop would at least encourage you to engage with enemies - right now they come so hard and fast and there is no reason to engage.
Nicely done. I enjoy slow, deliberate platformers in pico8.