Spheres are a form of "key" system on Bion in Metroid Prime: Federation Force. Spherical objects, generated from launchers appear in M02: Hardball and M16: Slipstream. They are used in security systems; which are unlocked by shooting the spheres into slots. In Hardball, four of these spheres are used to open a large door leading to the Orb. The spheres must be carefully moved toward their slots, without being destroyed to complete a bonus objective. On Hard Mode, they will explode after a period of time. In Slipstream, several sphere launchers are present on the ancient skiff and are usable as weapons. When pushed into catapults at the front of the skiff, they will be launched at the Pirate Warship. Spheres dropped by Flying Pirates can be used in the same manner.
The mechanics of these spheres are also tested when playing Blast Ball.