What happens when you combine "The Blair Witch Project," "Godzilla" and the ever-remaining images that continue to haunt our hearts and minds from New York City's 9/11 attacks?

Answer? You get "Cloverfield," a $30 million retro monster flick from producer J.J. Abrams and director Matt Reeves ("The Pallbearer"), in which a group of 20-somethings struggle to survive when New York City is attacked by an indescribable something.

The subject of the latest, greatest grassroots marketing campaign in the cinema world, "Cloverfield" begins rather playfully with Rob (Michael Stahl-David) and Beth (Odette Yustman)playfully filming each other after having obviously had sex. We flash forward a month later, and Rob is preparing to leave to take over a corporate vice-presidency in Japan. At a farewell party in his honor, Rob is joined by his brother, Jason (Mike Vogel, "Poseidon"), his best friend Hud (T.J. Miller), his brother's girlfriend Lily (Jessica Lucas, "The Covenant") and the object of Hud's awkward affection, Marlena (Lizzy Caplan, "Mean Girls") among quite a few others who are destined to not make it much past the film's first half-hour.

As Hud flirts his way around the party shooting goodbye testimonials, Beth shows up at the party with her new guy and, she and Rob fight, the two part angrily and then, of course, monster mayhem ensues and the battle for love and survival begins.

Does this sound, perhaps, predictable?

I assure you...it is.

Does this sound, perhaps, corny?

Oh, please, I guarantee you...it is.

Does this sound, perhaps, even stupid?

I swear on my alien baby's grave...it is mind-numbingly stupid at times.

BUT.

Oh my god, how "Cloverfield" entertains.

It has been quite some time since I laughed this heartily and jumped this anxiously in a film that, from the outside, seems so incredibly basic.

Almost despite itself, "Cloverfield" simply works.

That said, "Cloverfield" is destined to be a love it or hate it film.

Much like "Blair Witch Project," "Cloverfield" is seen entirely as a recorded video composed entirely of the video of the video shot by Hud that has been found as evidence of the day's happenings. Unlike, say, "Blair Witch Project," however, there are very few moments of stillness or peace or quiet that exist in "Cloverfield." Instead, the film often plays with the frenetic energy of, say, the Beastie Boys' documentary "Awesome: I Fuckin' Shot That" in which the band handed out 50 hand-held digital cameras to their fans and told them to keep recording no matter what.

Essentially, that's what happens here. If you hated "Blair Witch Project," then there's a good chance you won't fully appreciate "Cloverfield," though it certainly contains far greater special effects and action that may make up some of the difference. Likewise, if you find yourself made irritable by hand-held camera work, then "Cloverfield" is most definitely not the film for you.

"Cloverfield" is a physically demanding film, because the camera does shake nearly constantly and the story itself, as basic as it is, is far from a linear beginning to end story. If the screening audience I attended the film with is any indication, "Cloverfield" is likely to play better to a late teen, young adult audience. As the audience was leaving the theatre, it was impossible to not hear the younger audience members saying "That was awesome," while some of the film's older audience members were sort of groaning under their breath.

Having friends who live in New York City and who experienced 9/11, it's hard not to wonder how they would experience such a film that, despite Abrams' assertions otherwise, bears strongly the images native New Yorkers have tried to forget of a city devastated. Images of a decapitated Statue of Liberty are haunting, as are other images that, even for this native Hoosier, evoked memories of the Twin Towers.

These scenes do become easier to tolerate as the film moves forward, the monster is revealed and it becomes clear that "Cloverfield" is showing us a very different sort of terror.

As always happens in a monster flick such as this one, once the monster is on the scene Rob becomes determined to rescue Beth and is joined by the aforementioned friends on a journey that sometimes leaves you wondering who the real monster is...the creature, humanity or the U.S. military?

I'm still not sure.

Never completely terrifying, as one might expect given the PG-13 rating, "Cloverfield" is most effective because Reeves creates it with a slice of life feeling that perfectly blends moments of courage, stupidity, selfishness, hopelessness and outright humor.

While the storyline, from the immature, unbelievably stupid twenty-somethings who are seemingly quite wealthy to the laughably predictable "monster movie" behaviors, at times borders on laughably bad, Reeves reportedly instructed the cast to frequently ad-lib. The ad-libbing, even when laughably lame, makes even the most laughably bad dialogue and set-up in "Cloverfield" seem at least modestly believable.

This believability is enhanced, as well, by Reeves and screenwriter Drew Goddard's ("Lost," "Alias") refusal to sugarcoat the film or paint themselves into the stereotypical happy ending. "Cloverfield" is filled with monsters, great and small and within, and there are consequences for bravery and one could even say a streak of meanness towards the characters that is unnerving and uncomfortable.

At a mere 84 minutes, which includes almost 10 minutes for the closing credits, "Cloverfield" is a fast-paced, entertaining, anxiety inducing and surprisingly original take on a very familiar movie genre.

Somehow, "Cloverfield" exists as an immensely flawed film that remains immensely entertaining. Far more exciting than any of the recent monster flicks and infinitely more involving than Will Smith's undeservedly successful "I Am Legend," "Cloverfield" may be onscreen but its box-office prospects should prove to be quite stable.