Apparently, size doesn't matter after all. A massive and malevolent force threatens New York City, but it's seen only in fleeting glimpses through the tiny lens of an amateur videographer. And we're hooked.

What is plaguing the city? Terrorists? Aliens? A presidential candidate run amok? We won't tell. Though it has a gimmicky high concept, Cloverfield is a surprisingly gripping thriller. Employing a pseudo-documentary handheld camera style, it offers a fresh spin on the monster movie genre. Think Godzilla meets The Blair Witch Project, with a Gen Y Big Chill element thrown in. Then add homages to Alien, Independence Day and War of the Worlds.

The attractive cast is made up of relative unknowns, and initially we get caught up in piecing together bits of video footage and party gossip to determine the status of a romance between Rob (Michael Stahl-David) and Beth (Odette Yustman). We meet the couple in an amorous setting during the first few minutes. Not unlike a segment of some oddly addictive reality TV show, people hint at unresolved feelings and unspoken attractions. We're willing voyeurs.

Then the mood changes abruptly when a powerful jolt rattles a party being thrown for Rob on the eve of his leaving for Japan. Lights go out and panic ensues as reports surface of an earthquake and an oil tanker disaster. Partygoers take to the streets, where they see an explosion light up the skyline. The air is filled with smoke, and the atmosphere is pierced with screams and an ominous inhuman yowl. The military is called in.

A small band of partygoers faces down the unknown enemy: Rob, his brother Jason (Mike Vogel), Jason's girlfriend Lily (Jessica Lucas), Marlena (Lizzy Caplan) and Hud (T.J. Miller), who lusts after Marlena and provides much of the comic relief as he doggedly totes a video camera through the mayhem.

Ultimately, we do see the source of the terror, but the focus stays on the corps of relatable protagonists.

The film is rife with frightening moments and creepy things that jump out of the darkness. A note to the squeamish: If Blair Witch's camera moves made you ill, you might want to sit this one out. The genre may be old news, but the skillfully made Cloverfield offers a heart-racing experience with plenty of chills, thrills and exhilaration.