The movement controls feel really solid. The moment I saw a ledge grab in a Game Boy game I leaned forward in my chair to lock in. I do agree there's to tidying that can be done to help with iframes and some of the other edgecase mechanics like boxes on springs, but for a game jam this feels pretty polished.

Played you game on stream heres the VOD if you like to watch

https://www.twitch.tv/videos/2268541164?t=02h20m48s

Pretty standard as far as platformers go, although I ran into issues that forced me to restart several times, mostly getting stuck in a corner grapple when I shouldn't have - once on the edge of movable boxes. Also on level 1 if you push the second box gently, you can't pass either way if it falls dead center on the button, causing a restart. The third time was again on the edge of a box next to a trampoline, causing me the lock up and jump up and down in the "holding" animation.

That being said, the graphics and especially sound/music design is very good. Really catches the gameboy feeling spot-on. Great job there! :)

Great game, a little celeste feel in certain mecanic but really fun to play, I past the two level you had time to deliver. It's a good game for a week of dev

There's some serious potential here, the controls are quite polished, but gosh it needs invincibility frames, it feels like I get knocked about into other parts that deal damage every time I get hit, and getting hurt during the hurt animation where I can't move, making some parts feel impossible, particularly with that aggressive fireball spawn rate...
Oh and a visible lifebar would be nice too...

Controls are good and I like the level design too. I become stuck at some point in a small corner, character is hanging there but can't do anything, I believe I saw other comment showing this issue too. It was enjoyable to play.