Metroid Fusion is a 2002 action-adventure game developed and published by Nintendo for the Game Boy Advance. It is the fourth main Metroid game. Players control the bounty hunter Samus Aran, who investigates a space station infected with shapeshifting parasites known as X. Along with the GameCube game Metroid Prime, Fusion marked the return of the Metroid series after an eight-year hiatus following Super Metroid (1994).