Corallo is a Yume Nikki fangame. The main focus is exploring "dreams" and collecting "effects", which can be purely cosmetic or make the character perform certain actions.

Corallo focuses on Maya, a young woman stuck on a wheelchair and locked in a room. She can only stare at the ocean in front of her window and daydream.

By interacting with her mind, the player can learn more about her and her past, and what lead her to be stuck in her current room.