IF YOU ASK ME, the thing in Cloverfield is from Venus, although producer J.J. Abrams claims in the press kit that "Clover" is an up-from-the-depths monster. Imagine an authorized Godzilla movie where Godzilla doesn't appear in the title (not even under his American pseudonym Gigantis the Fire Monster): it would have been the biggest unbilled performance of all time.

The final shot of the mottled, expressionless, mildly curious face shows that code name "Cloverfield" most closely resembles Ray Harryhausen's Ymir from 20 Million Miles to Earth (1957); it is something ancient, simian, as puzzled as it is furious. But we never quite see him or her plain until the end. There seem to be tentacles. Certainly there's a tail and two large, heavy feet. The final views from an evacuation helicopter don't even make it clear that the critter follows the biological law of bilateral symmetry.

Abrams and director Matt Reeves' didn't really make this a Harryhausen-style character, either—alone, afraid in a world it never made and all that. Who-hit-whom-first is never a part of Cloverfield's plot, though its trimness and light-footedness make up for a lot.

One last quote from Abrams' pitch: "A Cameron Crowe movie meets Godzilla meets The Blair Witch Project." Even if you could do without the slice of Crowe in that particular sandwich, the beginning is a strain: 20 minutes of twentysomethings at a downtown New York City loft party. It's a tale filmed by an idiot (he is called Hud, and he's played by T.J. Miller) unschooled in the use a video camera.

"I'm documenting," he says, pushing his camera into various faces at Rob's surprise going-away party. Rob (Michael Stahl-David) is heading off to Japan to take a job; his departure is complicated by his unresolved thing for Beth (Odette Yustman). Somehow, I preferred Marlena (Lizzy Caplan), the standoffish girl, keeping away her fellow guests by concentrating on the electronic bauble in her hand. She's a stranger at a party where all the gossip is about the host. Jump edits condense four hours of blather and drinking. Suddenly, we get an earthquake and the unexpected arrival of the Statue of Liberty's head, rolling down the street like a bowling ball. People raise their cell phones to take its picture.

Cloverfield then segues to an hour-long attack with the survivors uploading their adventures as they take place. The monster is always just outside the camera's range; the rolling dust clouds familiar from 9/11 obscure the colossal shape stirring in them.

After our clutch of partygoers is prevented from leaving town via the Brooklyn Bridge (a mighty-fine sequence in itself) so they head uptown. Cloverfield's spastic-cam comes to rest in the fluorescent-lit negative space of the Spring Street subway station. There, the search party decides that the best way to head uptown is through the dark subway tunnels.

This film's faith in the military and in cell-phone technology seems a little naïve. Can we trust that the former has a contingency plan for giant monster attack? Or that the latter system would work if the power grid was being rearranged by something large and lawless? Suspend those points of disbelief, and Cloverfield seems less like a mash-up of familiar tactics and more like something unusual and inventive.

Cloverfield (PG-13; 90 min.), directed by Matt Reeves, written by Drew Goddard, photographed by and starring Lizzy Caplan, T.J. Miller and Odette Yustman, opens Jan. 18.

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