And smash is the word for this hyperkinetic extravaganza, which begins with a Middle East robot attack that turns a U.S. military base to shrapnel and concludes with a free-for-all in downtown Los Angeles that batters the city to smithereens. The connective tissue in between - you know, story, characters, romantic subplots, all that dull stuff - gets short shrift, but the film's propulsive excitement, logic-shattering action and absurdist humor deflects all criticism.

The heroic Autobots, led by Optimus Prime, and Megatron's evil Decepticons learn that the key to the Allspark's location lies with the unsuspecting Sam Witwicky (Shia LaBeouf), a likable nerd whose great-grandfather discovered it on a voyage to the Arctic Circle.

Being highly advanced products of a technological civilization far superior to our own, the robots settle their differences by blasting each other to splinters. Tyrese Gibson and Josh Duhamel run through the proceedings as dauntless servicemen who discover the chink in the aliens' armor.

If you're making a film whose goal is simply high-megaton fun, Bay and Spielberg are the dream team. Heavy-artillery fetishist Bay shreds the envelope in terms of battle scenes, giving us man vs. machine and 'bot on 'bot duels of heroic scale and breakneck velocity.

Spielberg is the gold standard in terms of technical sheen, passing along everything he learned about doomsday urban warfare from "War of the Worlds." You can see his perfectionism in the sequences where Cadillacs and Hummers transmorph into towering gladiators with sheet metal body armor. And he gives the project needed moments of humor, with a minor metallic rascal who tiptoes around the edges of the story only to be flattened, bashed and dismembered like a Meccano Wile E. Coyote.

The film is overlong at 144 minutes - there's a sequence in which the Autobots visit Sam's home that clearly doesn't pull its weight - but it leaves you with a blissed-out exhaustion. As a camera-wielding teenaged extra shouts while recording one of the film's nonstop cataclysms, "This is 10 times cooler than 'Armageddon!'" - and how.