This shows a cutscene picture of where JunkBall! takes place: a vast junkyard in the middle of nowhere.

Hidden within this decaying land of rust and scrap, lies a dangerous weapon able to annihillate an entire city. The weapon was accidentally left here while being taken to an airbase to be disarmed manually by its creators. 

Hazardous Maintenance Nanodroid #259, or the "JunkBall", as the creators have called it for the sake of convenience, is a tiny, marble-sized robot that can use a powerful electro-magnet to manipulate metal objects around it. Using this ability, it is believed that this robot may be able to go into this mysterious junkyard and disarm the weapon before it goes off.