ONE Aeolus is a first-person sci-fi action horror game with sandbox elements. You take control of an astronaut named Brian O'Callaghan, who one day wakes up alone on a spaceship after a long hibernation. He must find out where the entire crew went. The game takes place in the future, in 2035, when humanity has sent a group of colonists to Mars, aiming to find out what happened to the previous expedition to the Red Planet.