Nice work! I did a quick recording playing your game in case it's helpful: Crustacean Tomfooley by Memtimin | Cap Recording
I had fun shooting the angry flying boss as the crab, and clearing out all the homing red dot enemies. I also really liked the hit animation you put on the boss, it made landing my shots feel rewarding. Also really like your drawn assets, the crab especially.
With the enemies taking 2 hits each, it would be cool to play around either these only taking 1 hit, but having more of them, or similar to your boss introducing a visual hit marker. Right at the start I had a thought my shot didn't register, but quickly found out you just needed to hit them twice.
Overall a solid submission!