Junkers

ALIENS!!!!

When a distant sun starts to fade, the inhabitents, extremely tall organisms that breath oxygen and have a small amount of resistence to heat, leave their dying planet. Finding Earth suitable for their physical needs, they conquer the planet and create massive genocide against the main race that lives there. The remaining humans hide underground and in abandoned buildings, while the new rulers of Earth start to plan their empire.
Well is a survivor of the genocide and the son of a wealthy robotic engineer. With his understanding of robotics, he sneaks of during the day, when it's too hot for most of the newcomers to leave their yurt-like homes, and builds robots, hoping to create a massive army and destroy the alien tyrants.