Well the game is about as finished as it will ever be, and I just submitted it. It's nowhere near the quality of some other games submitted, but at least I have the excuse that I started 5 days late lmao. Since yesterday I've completely reworked the fish spawning, so there are now multiple types of fish. I've also added more phases to the boss fight, as well as sound effects. All things considered, it could have gone much worse!
link to the game: https://superplink.itch.io/fishfest-game
Well, one day and about 500 lines of code later, I made the game. Everything needed in the game is there, it just needs polishing. Since yesterday I've added 3 phases as well as a final boss. I'll probably add some particle effects to make it feel more responsive and satisfying, and maybe add some more art since it looks like utter garbage, but it is a playable game.