Well-made, just a really good and simple arcade game.
Character controller seems really floaty. I think it's possible to get very used to it, but the speed feels like it suddenly ramps up from nearly zero to flying over a very awkward transition period. It's a decent fit for this kind of game, since it adds to the skill level of the game, so I'm not really against it. You could even lean into this as a mechanic for increasing punch damage based on speed to punch the crabs even harder.
I didn't read the part about picking up stunned crabs at first, but it was fun enough with just punching. Definitely adds a lot more options and challenge with the throwing mechanic once I tried it. I would like it if you could also stun crabs by up-punching them as they're falling in the air, though.
Game could also use a countdown to the next wave, since nothing else is shown on screen while waiting for the next wave to start. Just feels like an awkward moment where nothing seems to be happening.