PG-13

With an intense viral marketing campaign complete with fake Web sites and MySpace profiles, “Cloverfield” positioned itself as a giant monster flick for the Web 2.0 world. Presented as a recording of a mysterious monster’s rampage across Manhattan, “Cloverfield” really feels like a post-apocalyptic artifact, dredged up from the rubble and covered in dead monster bits. Although it’s built around a conceit that could easily become tired, “Cloverfield” doesn’t let up, sticking faithfully to its premise and delivering all the necessary monstery goodness.

“Cloverfield” begins as a recording of a going-away party for Rob (Michael Stahl-David), who’s going to Japan to accept a job as vice-president of an unnamed company. Organizing the party is Rob’s brother, Jason (Mike Vogel) and his girlfriend, Lily (Jessica Lucas), both of whom want the evening’s events documented. Behind the camera is Rob’s best friend, Hud (T.J. Miller), a dim-witted guy who provides the movie’s comic relief. Rob’s party is first interrupted by some drama between Rob and his friend Beth (Odette Yustman), who have unresolved feelings for each other. Beth leaves the party angry, Rob gets sad and, shortly thereafter, an earthquake rocks the building and knocks out the power. As Jason, Rob, Lily, Hud and friend Marlena (Lizzy Caplan) head out to the street in search of safety, the nature of the disaster becomes a little clearer—a giant monster is rampaging across Manhattan. After a series of tragedies, Rob decides he needs to head across the city—directly into the path of the monster—to find Beth and make amends with her.

Sure, the core of “Cloverfield” is based on a gimmick, but the movie works because director Matt Reeves and writer Drew Goddard (who’s worked on Abrams-produced shows “Lost” and “Alias,” as well as “Buffy the Vampire Slayer” and “Angel”) deviate very little from the conceit. From the opening party scenes to the film’s final tense moments, the viewer sees everything the characters see—and nothing else. Sometimes, this is tedious. The opening sequence at the party is overly long, even if it is necessary to introduce the characters and firmly establish the handheld camera gimmick. The acting is predictably scattershot. There are moments when Stahl-David and the rest of the cast act like typical characters in a monster movie, spouting clichés and making foolish decisions. There are other moments, though, that seem very real, especially a quiet scene in which Rob answers a cell phone call from his mom and has to inform her that his brother has died.

More often than not, these attempts at verisimilitude work, and the results are evocative and creepy. The brief glimpses we get of the monster at the beginning of the movie only add to its mystery, and, later in the film, a skirmish between Rob and his friends and some mini-monsters in a subway tunnel is pretty scary. By the end of the movie, there’s perhaps too much monster, and the few up-close shots we get during the climax reveal more than they should.

Those mini-monsters are another thing that make “Cloverfield” interesting enough to separate it from other monster movies. There’s no explanation for their appearance, other than a short news broadcast Hud watches that shows mini-monsters dropping from the body of the giant monster and skittering down the street. In fact, there’s no explanation for any of the film’s events, even when Rob and company manage to wander into a military outpost inside a deserted department store. The soldiers, it seems, are just as clueless as the civilians, and the Army’s only strategy is to evacuate Manhattan and bomb the hell out of the monster. There’s no lecture about the monster’s origins or revelations about its potential weaknesses, and the film’s better for it. After all, what more do you need to know about a giant monster other than that it wants to smash things and eat people?

Like most giant monster movies, the beast in “Cloverfield” is a stand-in for a multitude of anxieties and fears. As Godzilla was to the atomic bomb, so is the “Cloverfield” monster to terrorism, natural disasters and all the other calamities that have occurred in the last decade. After the monster angrily knocks down a skyscraper, the clouds of dust and debris that roll down the street are an explicit reference to the collapse of the World Trade Center. Later in the movie, we learn—from a scene that’s both subtle and graphic—that the bite of those mini-monsters transmits some kind of horrible disease. And, as much as “Cloverfield” plays on these fears, it also exploits our desire to document them. When the Statue of Liberty’s severed head rolls onto a street, gawkers with camera phones surround it instantaneously and snap pictures. It’s not a stretch to think that the survivors of the monster attack, once safe and secure and someplace with Internet access, would upload their pictures and videos to YouTube and Facebook.

“Cloverfield” is never heavy-handed about this, though. Apart from some corny bits between Rob and Beth, this is a movie that’s all about a giant monster knocking down buildings and flattening people beneath its weird mutant feet. The “Cloverfield” monster will never be as iconic as Godzilla (the handheld camera POV doesn’t lend itself to giving the monster any sort of personality), but the film will likely be remembered for its non-monstrous elements, as an artifact from a time when digitally documenting every aspect of our lives—from complete happiness to devastating tragedy—was still somewhat of a novelty.