It is the year 2020, an alien invasion fleet attacks the NASA base on Mars, destroying it completely. The invaders, androids from the Planet Guk, then take complete control of the red planet. Their leader, Zelda, makes plans to take over the Earth as well. Meanwhile, the Earth's only hope for survival, the elite defence force codenamed TERRAHAWKS, stands ready at their secret H.Q, waiting for Zelda to make her first deadly move...