Incredible art style, very fluid animation and great choice of colors! I enjoyed the platforming and bosses, though I think the boss fights feel pretty linear. This is probably intentional due to the tight controls, but I think just a little more freedom could go a long way so the player feels like they at least have some level of control instead of following a very strict pattern, and could probably enable more skill-based patterns since this definitely seems like an intentionally hard game.
The boss with the bouncing projectiles was my favorite, reminds me of Wispy Woods.
Overall, great work!