Remember those long hours spent playing space invaders on your Atari, without imagining you might one day be called upon to save the planet? "Alex" (played by Lance Guest), a teenager living in a trailer park and working odd jobs, could turn out to be that person. At least, that's what "Centauri" (Robert Preston) believes. He orchestrates a scheme involving a convincing android duplicate and enlists Alex to stop the nefarious plot of "Kril" (Dan Mason), "Enduran" (Kay Kuter), and their powerful fleet of spaceships from taking over Earth. Will he succeed? Is he capable of stopping their clever strategy? It’s an enjoyable fantasy adventure, with Guest fully embracing his role alongside Preston. Numerous special effects help to overshadow the occasionally awkward romantic subplot involving "Maggie" (Catherine Mary Stewart). There's a good deal of humor present, largely thanks to Preston, and Guest is a likable hero for audiences to root for. It has aged remarkably well, as many straightforward concepts often do, and I found it quite entertaining.

Source on TMDB