Zero City is a mobile survival simulator that combines base-building strategy with RPG elements in a post-apocalyptic world. Players take command of one of the last underground bunkers, managing a community of survivors by assigning them duties, training them in new skills, and equipping them for combat. The gameplay centers on constructing and upgrading various specialized rooms to create an "impregnable shelter" while defending against constant zombie attacks. Beyond the bunker, players engage in a story-driven campaign and competitive PvP arena tournaments to secure resources and dominate other shelters.