Atomic Robo-Kid

In the 21st century, a blast of cosmic radiation bombarded Terra-12, a deep-space outpost of Earth, hideously mutating all transplanted life. A fleet of savage beings followed the radiation wave and invaded the planet and began the systematic destruction of all remaining sentient life. Years of battling the alien 'governors' have gone by, and now only one hope survives to avenge the desperate terran colonists.