Metal Arms is set on the planet Iron Star, built by an ancient race, Morbots, out of scrap metal and space junk. The Morbots are rumored to still inhabit Iron Star’s core, where none of the surface dwellers venture for fear of deactivation and destruction. As the life of Droids evolved, a scientist, Dr. Exavolt, experimented with Droid technology, attempting to evolve Droid technology beyond its current limits. Exavolt’s experiments were successful, however he could not advance Droid scientists. One of his experiments inadvertently resulted in the tyrannical military mastermind known as General Corrosive. Corrosive began manufacturing a race of soldiers known as Milbots, or Mils, and enslaved the Droid race of Iron Star. Droids who rebelled against Corrosive were deactivated and recycled. Colonel Alloy, a former architect, established a hidden Droid settlement known as Droid Town, where he and the Droid Rebellion make their final stand against the Mils.