Basement Mech Fights Alien Invaders

Genius scientist Nate Kane is arrested for treason after refusing to use his fusion tech for weapons. When aliens invade Earth, he escapes and builds a prototype mech in his basement lab with assistant Lana. He finds the invasion is led by his ex-colleague Rory. Nate upgrades his mech, raises a defense force, kills Rory and the alien leader, and repels the invasion.