Beauty shows how advanced your aquarium is. You can increase its Beauty by buying fish and decorations, something that also earns Stars for your aquarium.
You need Stars to:
– Unlock new aquariums. You need to earn a certain number of Stars in your current aquariums to unlock subsequent ones.
– Receive more coins. Every additional Star gets you bonus coins for the levels you beat.
– Earn diamonds or boosters as a one-time bonus. You get them right after you earn new Stars.