When a film isn’t screened in advance for critics, it is usually a red flag – a sign that the studio has little faith in its product.

For the most part, the warning proves to be prophetic, but there are a few occasions when a film manages to shatter that belief.

“Legion” is a film that fits neither category.

While the studio shouldn’t have hidden it, “Legion” does come off as middle of the road. It’s a movie that everyone will probably forget by the time the calendar hits 2011.

“Legion” is another in a long line of apocalyptic, end-of-the-world action films with a story centering on God losing faith in mankind and sending his legions of angels to end the world as we know it.

His orders are disobeyed by Michael (Paul Bettany), who heads to Earth to protect the one person who can save the world, the unborn child of a single mom named Charlie (Adrianne Palicki) who works as a waitress in a desert diner.

There are a few really nice moments in the film that make this a cut above most action films. The best sequence comes early, when an elderly woman turns into a blood-thirsty demon capable of scaling the walls of the diner (the scene is given away in the trailer).

The film also has a decent cast for a B-level film, with Dennis Quaid, Charles S. Dutton, Lucas Black and Tyrese Gibson among the people trapped in the diner with Charlie and Michael. Unfortunately, they are all given a script that is rather convoluted and leaves far too many questions. (I’m still not sure why the child is the chosen one.)

Director Scott Stewart, who also co-wrote the film, shows far too many scenes in which characters talk to try to cover up plot holes that bring the film to a grinding halt.

It’s unfortunate because when “Legion” concentrates on its action sequence, it actually has a little snap. Too bad the filmmakers took this material way more seriously than they should have, resulting in a film that quickly fades into mediocrity.

DVD dandy of the week

This week’s dandy is “Zombieland” (B), a mindless bit of fun with a strong cast milking every ounce of entertainment out of a pretty clever premise.

Jesse Eisenberg from “Adventureland” stars as Columbus, a neurotic college student trying to survive after Earth’s population has been decimated by a mad-cow-related disease that turns people into flesh-eating zombies.

Columbus is hoping to get back home to see whether his family is still alive, but his plans change after he joins forces with a redneck zombie slayer named Tallahassee (Woody Harrelson) and two sisters (Emma Stone and Abigail Breslin). The quartet sets out on a cross-country trip to California, hoping to find a rumored safe haven for Earth’s last survivors.

With a smart and funny screenplay from Rhett Reese and Paul Wernick as a blueprint, director Ruben Fleischer gets plenty of mileage out of “Zombieland.” There are lots of laughs between the icky moments, including a surprise cameo that is best left a secret.

The four leads also help make “Zombieland” a lot of fun. Eisenberg is the perfect unlikely protagonist, while Harrelson makes an amusing sidekick. Stone and Breslin also are good in their respective roles.

If I had any complaints about “Zombieland,” I’d have to concede that there really isn’t much of a point here – except to serve as mindless entertainment. On that level, “Zombieland” more than succeeds, giving audiences a chance to put their brains on autopilot and just enjoy the show.

“Zombieland” is rated R for horror violence/gore and language and will be available on DVD on Tuesday.

– Sportswriter/movie reviewer Micheal Compton will be attending tonight’s Nashville screening of the Sundance Film Festival entry “The Extra Man,” starring Kevin Kline and Paul Dano. To get his thoughts on the film and his report on the Q&A following the screening, visit his blog at mcompton.wordpress.com or his Twitter page at twitter.com/mcompton428. You can also e-mail him at mcompton@bgdailynews.com.