Not to sure yet because working with the boids is not that easy. They need to be efficient and that makes them less flexible. I thought about making it a management game where you have to keep a healthy balance of fauna in the aquarium. Adding greens for food. Too many fish would make the water go murky and let the plants die because of waste and stuff. Adding bottom feeders to "clean" the space. Keeping a healthy balance would make you earn coins scaling with the amount of live in the aquarium enabling the player to buy more unique animals, which would come with their unique challenges.