Transformers have always been boy-toys. I know plenty of women who grew up on Spider-Man comics. I don't know a single one who went around jiggling the gun-wielding robot-cum-truck Optimus Prime.

This may explain why, of all the summer blockbusters, this one feels the most macho.

Just as crucial is the presence of director Michael Bay, the shock 'n' awe maestro behind Armageddon and Pearl Harbor. As one of the film's actors says in the press notes: "He's not Elia Kazan."

We're barely settled in our seats before the bombardment begins. In sand-blown Qatar, a bunch of US Air Force men are attacked by God knows what. These soldiers are typical Bay protagonists: chiselled temples to American might. When an excitable Latino colleague speaks in Spanish they yell: "English dude, English!" All the while, they're being helped by a local urchin. I waited in vain for him to meet their inquiries with " Arabic, dude, Arabic!"

Elsewhere, Bay is determined to show a softer side, a mission aided by his choice of star, the promising Shia LaBoeuf. LaBoeuf has been dubbed the new Tom Hanks and while he's surely too odd-looking for that label to stick (a cross between Depeche Mode's Dave Gahan and a troll doll), he's certainly as talented.

His Sam Witwicky is a car-obsessed, girlfriend-less geek, prone to nervy introspection (the camera jump-cuts when he looks in the mirror) and bright-spark charm that works wonders with teachers but gets him nowhere with beefy jocks.

Sam thinks his life will change when he has a car, and he's right. The vehicle he ends up with - a mashed-up Camaro - is actually an alien life form called an Autobot (a good Transformer), not a Decepticon (a bad Transformer).

Both the Autobots and the Decepticons think Sam can help them locate an energy-supplying cube called the Allspark and Sam is soon being chased by everyone, from hysterical, possibly drugaddled policemen to psychotic agents from the CIA.

Via Sam, Transformers explores the idea that the majority of males are pre-programmed; that they are obsessed by speed, conflict, sport and, by extension, war. And if that sounds a little hi-falutin' for an action flick, remember that the film's executive producer, Steven Spielberg, made A.I., which took the fine line between men and machines very seriously. Toys are us, indeed.

This is the aspect of the film that grips. And, hey, the transformy stuff isn't bad either. We see a Decepticon twirl like a Rubik'scube in mid-air and hit the ground (a busy motorway) running. Even in slo-mo, it's shockingly fast and furious.

In Crash, David Cronenberg's apocalyptic vision of the future, two damaged lovers make out in a lay-by as careering cars roar by. That audiences may be similarly stirred by the carnage caused here is not good - but it's surprisingly easy to go with the flow.