Marshmallowville may be just another spec on the map, but lurking beneath the surface of this tiny marshmallow-manufacturing town is a "Marshun" menace that threatens the very safety of our planet! Will the Marshun invaders drain the energy ore of Earth, leaving it uninhabitable, or can Johnny Blaster and M-Force send them scurrying back to Mars with the help of Professor Fluffernutter's marshmallow-firing inventions?