In Subterranea , a treasure hunter must navigate through Hexuplex Caves to collect crystals. The goal is to blast aerobots guarding the cave and avoid obstacles like skulls and walls, which will drain energy. As the player progresses, the caves narrow and enemies become faster. If all reserve rangers crash, the game ends.
Gameplay involves controlling a cave ranger, shooting down various types of aerobots on each level. When all bots are destroyed, a passageway opens to proceed deeper into the caverns. The player must use energy efficiently and avoid obstacles to progress through the levels. The difficulty increases as the player moves from one set of caves to another.