The world is endangered by the return of the most powerful superhero ever to turn bad. Thought to have been killed long decades ago, Concussion (Kevin Zegers) is still alive and is blasting his way through space/time and multiple dimensions to return to seek vengeance on Zoom (Tim Allen). Unfortunately for us, Zoom is completely unaware of the threat, and is working in an automotive repair shop, having lost all of his powers years ago.
When Dr. Grant (Chevy Chase), a scientist working for the top-secret organization that had recruited Zoom and helped to develop his super powers way back when, discovers that Concussion is, in fact, alive and headed back to Earth, he is instructed by General Larraby (Rip Torn) to retrieve Zoom and press him into service helping to train new superheroes. Assisting Dr. Grant in this task is the overly-anxious, yet forever clumsy Marsha Holloway (Courtney Cox), a scientist for the same top-secret organization and, quite possibly, Zoom's biggest fan; she has a collection of every Zoom comic ever made. The problem is, Zoom is not interested in returning to a life having to do anything with super-heroics. He is not the heroic youth he once was and is, instead, more interested in money and self-interests.
This pretty much sets up the dynamic in Zoom. There is tension between the need for Dr. Grant and General Larraby to successfully get a Superhero team that can defeat Concussion in time for his arrival, the tension between Zoom's reluctance to be heroic again and Ms. Holloway's need for him to live up to the comic books and the struggle to recruit and train a group of kids as the next superhero team. Add paint balls and an old captured UFO and hilarity ensues.
I found the movie to be a bit slow, concentrating a lot on character development, rather than a lot of action. This is much more of a comedy with superhero elements (and gags) than an X-Men movie with some laughs thrown in. The main fight sequence in the movie is not very graphic at all (read, "Mild Action") and is fairly brief, occurring very near the end of the movie.
If you're looking for an action-packed superhero movie, Zoom is not it. However, if you want to watch a comedy that will be interesting to kids and won't last too long (88 minute run-time), then Zoom will give you a nice, entertaining story without having to explain too many things away.