Theme, Message and Aesthetic wise this game is on point with the Game Jam honestly. Sound wise, what was there worked, but it felt really lacking. There was a sever lack of Game Feel/Feedback.
While mechanically the game worked really well, I found it lacking in Scope/"Aim wise?". Since I could pretty much skip any and all levels any time I wanted. I couldn't exactly tell, from my end at least, Which fish was healthy and not, so I just killed them all with 0 consequences. Picking up the trash in this game just felt like a chore instead of an actual accomplishment/achievement to be done, and had 0 reward for doing so.
It has great amount of potential, but in my opinion, I would lower the scope of having more levels and focus on making that single level as fun as possible. And this is a game to keep an eye out on post Jam, as from what I have seen, your code is fundamentally solid, its only the presentation that needs more polishing up.
Great job mate ^^