RATING |

"I Am Legend" features Will Smith as the last man on earth, slowly going nuts in a New York City empty of people, but infested with nocturnal zombies.

Smith studies the rampaging cannibals for some flickering sign of humanity, to no avail.

"Social de-evolution is now complete," he sighs, after watching a mutant mob eat a live deer. "Typical human behavior is entirely absent."

Dude, haven't you ever been tailgating?

"I Am Legend" is a big change of pace for Smith, Hollywood's most invulnerable leading man, an actor with an impenetrable armor of confidence and a smile that's as close at hand as a happy ending.

"I Am Legend," though, is a downbeat affair, and Smith goes all pessimistic and somber to play Robert Neville, an army doctor who uses his ample spare time to find an injectable cure for the virus that's turned humans into a ravenous horde, unafraid of anything but sunlight.

Neville is naturally immune (one of several whoppers the script is happy to gloss over), and he hopes that others have survived - each day he sends out a radio broadcast, asking prospective listeners to meet him at the South Street Seaport.

The rest of the day is spent with his trusty German shepherd, foraging for food, hunting deer on Broadway, driving his red Mustang at 100 mpg through the Big Apple's empty streets.

It's this vista of an abandoned metropolis that should give a movie like "I Am Legend" an enjoyable, sci-fi kick. Sure the world's been depopulated by a sickness, and billions of people are probably dead, but still - wouldn't it be fun to have free rein of New York?

Nope, says the relentlessly grim "I Am Legend." Its priority is the psychological realism of Neville's advancing mental breakdown, made darker by gruesome flashbacks that show us the last days of the New York, of his former life as a family man.

At the same time, the movie knows it must satisfy the commercial, ooh-ahh demands of being a big-time holiday spectacle, and so it invites us to gawk at its special effects, at the wonder of a lion eating a deer in Times Square. "I Am Legend" also dangles the possibility of a religious-themed, hopeful conclusion. This feels like a subplot added after somebody at the studio evaluated the "Narnia" receipts.

You end up with a movie that looks slick, but one that's not very much fun, and not very deep. "I Am Legend," despite its glumness, ultimately feels like a watered-down version of more thoughtful doomsday movies like "Children of Men," or "Sunshine" or "28 Days Later." Or "28 Weeks Later."

Holy moly.

That's a lot of apocalypse, and we haven't even mentioned "Apocalypto."

What will filmmakers do if it turns out the world isn't coming to an end? *

Produced by Akiva Goldsman, James Lassiter, David Heyman, Neil Moritz, directed by Francis Lawrence,written by Mark Protosevich, Akiva Goldsman, music by James Newton Howard, distributed by Warner Bros.