The player(s) control a ship set in a series of interconnected areas. Each area has a core in the center that is constantly growing, as well as having several Planet Protector enemies. It is usually in the player's best interest to clear out each area of Planet Protectors by shooting them, then carefully inching their way to the protective barrier by an exit in order to drill through it. Once the barrier has been disabled, the player can then fly into the next cavern.