An underwater game engine? Idk Space to swim. Tip: spam space How to get cheesy puffs's: Get past the shark and collect it, you will be holding it. Then bring it to the top to score a point. Fish push you back.
got music from this project https://scratch.mit.edu/projects/764437061/ but originally comes from Mario. same for the game over sfx from https://scratch.mit.edu/projects/420488929/