I've just spent 2 1/2 hours watching a movie and another hour thinking about what I saw and I have no earthly idea what "Transformers: Revenge of the Fallen" is about. (About an hour too long, perhaps.)

There is a semblance of a plot. Shia LaBeouf and Megan Fox return as Sam and Mikaela, whose romantic pairing is again the most suspension-of-disbelief-straining element in a film about giant alien robot warriors that live among us disguised as General Motors vehicles. Caught in the midst of battles between nasty Decepticons and human-friendly Autobots, the kids race from California to the Mideast looking for the sun's "off" switch, installed long ago by extraterrestrial bad guys.

But combing through this audiovisual blitzkrieg for logic, substance and character is like looking for the poetic subtext of a monster-truck rally. The film exists as a pure sensory event, a pummeling, thrilling, bewildering, demented exercise in computer-generated shock and awe.

Director Michael Bay sprays visceral thrills at us with a fire hose. Aircraft carriers are torn in two. Tanks are scattered like bowling pins. Paris is strafed and the Pyramids are reduced to rubble. Mechanoid behemoths pound the rivets out of each other. Megan Fox straddles a motorbike in cutoffs that would give Daisy Duke heart failure. Oh, sorry, spoiler alert.

Whether you love or hate "Revenge of the Fallen" will depend on how you feel about crashes, explosions, gunfire and hot chicks. (Sam spends one day in college, where the student body seems to have been admitted on the basis of their modeling portfolios.)

If your reaction is, "Yeah, bring it on," ROTF's garish spectacle will fill you with childlike glee. If your standards are more demanding, ROTF will make you ROTFL at best.

Sometimes we yearn for a movie that will allow us to turn off our minds, but "Return of the Fallen" doesn't respect our intelligence. When the film shows us the Pentagon, Bay helpfully supplies a subtitle explaining, "The Pentagon -- Washington D.C." A Parisian sequence features a couple eating escargot in a sidewalk café and being accosted by a mime, because, as you know, this is what happens in France.

The script is an avalanche of genre clichés. There are notions, scenes and dialogue lifted verbatim from "Close Encounters," the Indiana Jones movies, "Gremlins," "Star Wars," "The Matrix" and the "Terminator" franchise.

The comic relief is as overdone as the pyrotechnics. Bay includes two shots of a Chihuahua humping a pug, and follows it up with a lusty little robot doing the same to Fox's leg. Returning as Agent Simpson, John Turturro exposes his pasty mudflaps for no earthly reason, and the expanded Autobot team introduces a pair of jive-talkin' carbots that are the most tactless ethnic stereotype to hit science fiction since Jar Jar Binks.

With choice dialogue like "Punkass Decepticon, any last words?" you're grateful that most of the talk is drowned out by explosions. I still wish I hadn't heard Turturro, calling in an artillery strike from between a behemoth robot's legs, say he was right underneath the thing's -- er -- Decepticles.

Acting is forbidden in Michael Bay movies, so it's forgivable that Fox poses her way through every scene of danger, romance or high jinks with the same moist-lipped, vacant air. She does a fine job of running away from explosions in a skintight halter top, an action she is called on to perform 7,005 times. LaBoeuf has a couple of Jerry Lewis moments when implanted alien information comes spilling out at college.

Oddly, it's Kevin Dunn and Julie White as his sit-commy mom and dad who create the film's most full-bodied characters. Despite a load of sentimental gloop about Mikaela's undying devotion to Sam and his parents' difficulties letting go, the movie's emotional high point is his farewell scene with Bumblebee, his yellow-and-black Autobot protector, who doubles as his Chevy Camaro. The big lug cries buckets of wiper fluid as Sam leaves home.

With 42 new robot characters, it's difficult to sort out the various giant Tinkertoys smashing each other in the frenetic battle scenes. The conflicts make about as much sense as sandlot battles fought by 8-year-olds wielding their Hasbro Megatrons, Starscreams and Optimus Primes. It's all sound and fury, signifying nothing. Bay has unleashed his inner child with the most expensive toy set in the world.

ccovert@startribune.com • 612-673-7186