Under A New Sun is a survival adventure game where you awaken from cryosleep to find yourself stranded on an alien planet after your colony ship crashes. With no crew and the wreckage of your ship surrounding you, you must adapt to this unfamiliar world, which contains both Earth-like flora and completely alien species. The planet has breathable air and a variety of environments, including various islands, underwater locations, and mysterious ruins, which you must explore to find out what happened to your mission.