After an extraterrestrial species subjugates Earth and forces humanity into servitude, a garage mechanic seizes an opportunity for rebellion by commandeering an advanced alien war machine known as the MASTER. Armed with this stolen prototype vehicle, he launches a lone resistance against the occupying forces, navigating hostile terrain and engaging in intense combat to push back the alien threat. With humanity's fate hanging in the balance, he must master the MASTER's weaponry and capabilities to mount a credible challenge to the invaders' overwhelming dominance and reclaim the planet.