Great art and animations, enjoyed the wacky intro sequence. Test font and redrawn godot logo is cute.
Bosses seem to have more invuln frames than the player, especially the mushroom boss. And the game crashed in the skeleton valley.
Sound cues really help with the bosses, but the audio was turned off by default which I didn't notice during the slime boss fight.
Also for some reason when I first set the game to fullscreen - the screen was flashing every second or so. When I exited - the game went borderless, so I couldn't change it's position. But after that the fullscreen wasn't flashing.
I really like it, but I suck at these kind of games.