Subnautica: Below Zero is an underwater adventure game set on an alien ocean world. It is a new chapter in the Subnautica universe developed by Unknown Worlds Entertainment. Released in May 2021 for PS5 among other platforms, the game combines exploration, survival, and sci-fi elements. Players dive beneath the icy surface of a frozen planet to discover new biomes, creatures, and uncover the mysteries of the alien world, while managing their oxygen supply and surviving in the harsh environment.