Simplify the following text for a Grade 7 native English-speaking person.
Original: 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 ) .
Simplified: The player controls the Guardian in human form while walking on Naju 's surface , called the `` Labyrinth '' . When in Naju , the Guardian turns into a spaceship in which the player can move around .