Cloverfield ***

What if you were videotaping a going-away party for a friend in Tokyo the day that Godzilla showed up? That is the premise for this cinema-verite style movie, except that instead of Tokyo, the city is New York, lower Manhattan, where a crowd of twenty-somethings have gathered to send off Rob (Michael Stahl-David), who's on his way to Japan as a newly-minted vice president. But instead of some guy in a lizard suit kicking over cardboard boxes, you have glimpses of a convincing, huge CGI monster that claws down skyscrapers, throws the head of the Statue of Liberty into the street in front of your apartment, and spawns creepy giant spider-things that bite all in their path.

The result is disorienting and truly scary. The movie starts without any credits as the playback of a piece of evidence in the Department of Defense "Cloverfield" file, presented as a video found in "what used to be known as Central Park." There are two stories on the tape. The first starts with an as yet unnamed Rob and a girl who wakes up in his bed (Odette Yustman), talking about going to Coney Island. These two seem to have something going. There is more of their day but then the scene abruptly changes to the party, where Rob's friend Hud (T.J. Miller) has been tasked with taping testimonials for the going-away party.

As events unfold, Hud retains his role as documenter and historian, as he, Rob, and a few others (including standout Lizzy Caplan as Marlena) embark on a quest to rescue the girlfriend farther uptown, where it's really dangerous. We learn that the tape they're using is one Rob left in his camcorder, so every once in a while we get the palimpsest of Rob's day with Beth, calm and sunny, but mostly we get the jittery handheld work of Hud as the group tries to survive long enough to get to Beth's place, where's she's trapped. The two stories comment on each other, and the end of the day with Beth makes a fitting ending to the movie. The emotions and motivations of the group, and of Rob are a mixture of guilt, fear, and some sense of community, that still doesn't quite turn these yuppies into adults.

The producers opted for little-known actors, and poured their money into special effects, and while they're not the seamless, eerily convincing effects of "I Am Legend," they are first rate. The convention of the hand-held camera making a last record goes back to "The Blair Witch Project" (1999), and here lends a similar feeling of reality captured on camera as it happens, and not as it is constructed by a writer, a director, a cameraman, and an editor. Cinematographer Michael Bonvillain deserves high marks for keeping to the convention, and while the jerky images take some getting used to, they are very effective. All in all, "Cloverfield" is an entertaining white-knuckle ride that creates a frightening new world that, at the end, you're glad to awake from.

Rated PG-13. 85 minutes. Directed by Matt Reeves. Written by Drew Goddard. Produced by Michael Bonvillain. Distributed in the U.S. by Paramount Pictures. Principal actors: Michael Stahl-David, Mike Vogel, Odette Yustman, Lizzy Caplan, Jessica Lucas, T.J. Miller .