Nice one! I did a quick recording of my gameplay in case it's helpful: Craballoon by Lerg Bwo | Cap Recording
A fun simple mechanic executed really well, perfect for a game jam. I like the vertical awareness needed while navigating the level, and also learning to pass over to other crabs efficiently in a left>right>left>right rhythm felt super rewarding. I liked the drawn assets too are nice.
When I was launched into the game, I was a bit confused and died quite quickly without being able to figure out what I was doing wrong. It was pretty easy to figure out what to do, but took me a few attempts before I went "aha I got it now". I wonder even for the first attempt at each level, having a 'ready' screen where all crabs are frozen until the first movement might be nice. Or even a smaller tutorial level as Level 1, with 2 other crabs which spawn quite far away.
I had lots of fun playing, excellent work!