Arrow keys to move. Eat smaller fish to grow bigger. Avoid being eaten by bigger fish. Don't touch the sea floor. Play in fullscreen.
Technically a collab, as @Blizzard_2 told me that he really wanted it to be an openworld game, so I started this project. Updates (MM/DD/YYYY): 05/27/2023: Project started 05/30/2023: Project published. Small bugs are present, but I'll just say that fish spawn on top of you.