More than meets the eye? Maybe a little, but not much.

Opitmus Prime, a member of an alien race, comes to help save Earth in "Transformers." Click photo for larger image. 'Transformers' Starring: Shia LaBoeuf, Josh Duhamel. Director: Michael Bay. Rating: PG-13 for intense sequences of sci-fi action violence, brief sexual humor, and language. Web site: transformersmovie.com Related articles Family Film Guide: 'Transformers' Tuned In Journal: Optimus Prime Speaks!

Then again, filmgoers can't reasonably expect more than pyrotechnic porn from a big-budget summer action flick based on a 1980s line of toys, comic books and a cartoon series. Fans of Optimus Prime and the gang will likely be satisfied by director Michael Bay's lively "Transformers," but at a bloated 144 minutes, the metallic movie wears out its welcome.

Perhaps to the surprise of some Bay detractors, the blow-'em-up director is most successful with scenes and set pieces that prominently feature flesh-and-blood humans.

The climactic robot showdown in downtown Los Angeles is a computer-generated whirl of visual incoherence that allows the mind to drift to shopping lists and weekend plans. But with the humans, Bay gets it right. Granted, they tend to be of the cardboard and stock variety, but this is a potential blockbuster, not Oscar bait.

Shia LaBeouf ("Disturbia") stars in "Transformers" as Sam Witwicky, a horny high school junior who's eager to buy a car to impress a girl. Any girl would probably do, but he's particularly fond of Mikaela (Megan Fox), who hangs on the arm of a churlish jock, because, she says, "He's hot."

Megan Fox, left, and Shia LaBeouf are pursued by aliens in "Transformers." Click photo for larger image.

Sam's dad (Kevin Dunn) helps him buy a car that turns out to be the Autobot Bumblebee, one of the good Transformers.

On the other side of the planet, a bad Decepticon Transformer terrorizes U.S. Army Capt. Lennox (Josh Duhamel, TV's "Las Vegas") and his team after destroying a U.S. military base in Qatar.

At the Pentagon, Defense Secretary Keller (Jon Voight) manages the response to the menace, which turns out to be of alien origin. Autobot leader Optimus Prime (voiced by Peter Cullen from the '80s "Transformers" cartoon), who isn't glimpsed until an hour into the film, explains in narration at the film's start that the Transformers hail from the planet Cybertron.

Ultimately the three threads -- Sam, Lennox and Keller -- come together as the mystery of the Transformers and Sam's ancestral connection to them is revealed.

Writers Roberto Orci and Alex Kurtzman (writing partners on TV's "Xena" and "Alias") strive to imbue the robot characters with personality, particularly in a funny bulls-in-a-china-shop backyard scene at Sam's house, but they're outdone by the special effects. Once the chrome characters transform from vehicles into robots they're highly detailed but indistinguishable, especially in action scenes.

Audiences get some relief from the look-alike iron giants with the human actors, especially in welcome comedic cameos by Bernie Mac, Anthony Anderson and recent Tony winner Julie White, who makes the most out of a small part as Sam's tipsy, nosy mother.

Film purists, who probably won't be rushing out to see "Transformers" anyway, might gag on their Junior Mints at the amount of product placement in the film. The credits even list a "product placement coordinator," who was likely responsible for ensuring all the brand logos made it into the movie, including cars, a fast-food chain and tons of toys made by Hasbro, longtime manufacturer of the Transformers action figures.

Although it lacks the same heart and soul that defines the "Spider-Man" franchise, the "Transformers" movie is a fun if overlong ride for audiences craving a few rounds of Rock 'Em Sock 'Em Robots on the big screen.