I'm getting this "stuck floating" bug a ton too - got it five times in a row right after getting the ice block and have to force restart the game. When trying to replicate (on Playdate hardware) I've been able to get it to happen in the room below the first statue with the rat (though I've seen it in other rooms) but I'm still not sure what causes it - I think something to do with switching items while levitating, or switching items too fast, or something. Maybe I play weird.
Basically the character animation stops working, and you're able to sort of jerkily move all around the screen (even with up and down on the d-pad), snapping back to above the levitation cloud if you don't move in a staircase pattern. Weird bug, probably something with pulp. Got one hard crash too but that seemed to happen out of nowhere when I was just moving to the right, so no idea on that one.
Edit: and right after posting this, hit a bug where after using the save teleport and saving after getting the third key, the game crashes every time I leave the room so I have to start over now. Bummer, great game apart from the bugs.