The hell... this is one of the games that look horrible or weird but fun to play with a bit of humor. Fighting crabs and shadow crabs until their daddy boss crab get mad and join the fight throwing his own children haha.
Yeah it is fun to play and if you want to improve this, maybe decide and be consistent with art direction so the sprites/images look like they belong together. Most stuff that needs fixing here are the visuals like the floor tiles. The others are spawn logic and boss aiming logic - he always shoot at bottom right and I am open wide to his right side.
Overall, it is cool. Congrats making a functioning game within the time frame. In the end, this is a game jam. We use whatever resources we gotta use to make the game.