This is a very charming game with a lot of kooky humor! I got stuck on the first fight because half the time I just get yeeted immediately, and the other half I just can't seem to deal enough damage to win. Though this does fit perfectly within all the rules of the jam, to me it just doesn't carry the spirit of a Game Boy game because it's a very clearly a visually modern 3D game made to look like it's on a Game Boy, but otherwise it's nearly full marks.
I also noticed a slight bug where the game over screen appears to transition away, but goes right back to the screen until the fanfare is finished playing.
Great job with this!