Gameplay varies depending on the player's location within Naju. The player controls the Guardian in humanoid form when exploring the surface of Naju (the Labyrinth) and in spaceship form when investigating Naju's interior (the Dungeon).[1]: 10  The Guardian has a life meter that decreases after sustaining damage from enemies; it can be replenished by collecting various items. If the life meter runs out, the Guardian explodes, and the game ends.[1]: 7  The player can use a primary rapid-fire weapon with unlimited ammunition as well as various powerful secondary weapons that consume "power chips" with each use.[1]: 6  Power chips are also used as currency to purchase upgrades for the Guardian in a handful of shops throughout Naju. Found within the Labyrinth or obtained after defeating a boss, these upgrades include primary weapon improvements, new or upgraded secondary weapons, and round, brightly colored creatures called Landers.