There's not much to say here really, cute theming, a bit on-the-nose dialog, cool bossfight, though you'll probably want to work on the platformer physics:
- From what I can tell, there's a constant vertical speed when you're falling, so when you jump, it's not a smooth parabola, but after your jump you immediately start falling at a high velocity, this just feels unnatural.
- Variable jump height is usually a good idea (halve the vertical speed once you release the spacebar and are still going up after a jump).
- Having horizontal speed "approach" your movement speed over time is usually a good idea (as opposed to just being instantly set to your movement speed). This is especially important for walljumps, because it creates that smooth circular shape of your jump, as opposed to moving away for one tick and then instantly snapping back to the wall.
- Also, you probably only want to wallslide if you're moving towards the wall. Otherwise most players will have an unexpected "why am I falling down so slowly? Oh it's because I'm falling next to a wall, even though I was going the opposite direction" moment.
- "Coyote time" is almost always a good idea: for a couple frames after walking off the ground you can still jump, and even if you press space a couple frames before landing, you also jump. This corrects for human error, and you usually want your games to be slightly biased in favor of the player.
GMTK and Jonas Tyroller have some good videos on making platformers feel right.