The space colonist in Colonials is named Zax. He was part of a team commissioned by the Martian government to explore nearby planets and establish colonies. However, before they can reach their destination, their ship is ambushed by a Moon-based civilization called the Lunars. Zax barely manages to escape the crash, but he sustains serious injuries and loses his memory as a result.
In his search for answers, Zax stumbles upon a group of humans who have been living in hiding from the Lunars for years. This group, now calling themselves the Resistance, were once part of the Lunar army but rebelled against their leaders after discovering their sinister plot to take over the entire galaxy.
The Resistance recognizes Zax's potential as a valuable ally in their fight against the Lunars and helps him regain his memory through a series of exercises and experiments. Together, they devise a plan to take down the Lunar army before they can further expand their control over other planets.
Throughout the movie, Zax and the Resistance encounter many obstacles, including traitorous members of their own group and advanced Lunar technology. But with their determination and Zax's newfound abilities as a result of his Martian biology, they manage to outsmart the Lunars and save the galaxy from human extinction.
The movie ends with Zax reflecting on his journey and ultimately deciding to return to Mars and help rebuild the colonies there, now with a newfound appreciation for the diversity of life in the galaxy.