After civilization crumbles, the surviving apes retreat to an underground bunker while scavengers claim the devastated surface world. With resources dwindling and threats multiplying in the depths below, players must balance foraging expeditions into the hostile wasteland against the constant pressure to gather supplies, fend off dangers, and make it back to safety. Survival hinges on smart decisions about when to venture topside, what to take, and whether the risk of extraction is worth the reward.