If you rolled every disaster movie into one spectacular package, you would wind up with something close to 2012, Roland Emmerich's latest apocalyptic fantasy.

This time Emmerich and co-writer Harald Kloser use the Mayan calendar and other end-of-days prophecies for their doomsday scenario, which imagines the world coming to an end in 2012. Eye-popping special effects ensure that the Columbia Pictures release will be a smash hit once it opens on Friday.

But while it's entertaining for most of its excessive (156 minutes) running time, the cheesy script fails to live up to the grandeur of the physical production.

Stitching together highlights from Earthquake, The Poseidon Adventure, Volcano, and even Titanic, the movie follows the fate of a dozen characters as they fall victim to a series of calamities brought on by some kind of solar meltdown. The issue is not so much what caused the cataclysm but how humanity will respond to the crisis. A venal presidential adviser (Oliver Platt) has the task of handpicking the people who will be allowed to board the atomic-age equivalent of Noah's ark. So the film aims to ask profound questions about how we choose the people worth saving. But profundity is not the director's strong suit.

Luckily, Emmerich's movies -- which include the disaster flicks Independence Day and The Day After Tomorrow -- never take themselves too seriously, so it's easy to enjoy the often laughable dialogue without balking. Credibility takes a flyer near the start, when an amateur pilot (Tom McCarthy) is able to steer a small plane through all kinds of fireballs and find his way to a tiny landing strip in Yellowstone National Park. You know the major characters aboard the airplane (John Cusack and Amanda Peet) aren't going to meet a fiery death this early in the movie, so you tolerate the ludicrous plot device.

Every disaster movie derives its suspense from trying to guess which of the characters will survive and which will expire. One of the disappointments of 2012 is how predictable the crash-and-burn list turns out to be. As in many of these epics, the characters who have committed some kind of extramarital transgression are the ones marked for death. Cecil B. DeMille would have been pleased.

Technically, Emmerich and his crew bring off a series of wonders. The movie hits its peak early on, when Cusack drives a limo through the streets of Los Angeles as freeways and skyscrapers crumble all around him from the shock of a 10.5 earthquake. The preposterous flying sequence is equally thrilling. The climax occurs aboard the giant ark, when an equipment malfunction almost threatens the entire mission. Unfortunately, this crucial sequence is not filmed or edited with the requisite clarity. Say what you will about Titanic, but James Cameron did a brilliant job of photographing the spectacular shipwreck so that the logistics were always crystal clear. In 2012, by contrast, Emmerich leaves us befuddled as to exactly what is happening to whom.

On the other hand, Emmerich deserves credit for offbeat casting. Cusack supplies his trademark hangdog charm, and McCarthy (recently better known as the director of The Station Agent and The Visitor) has perhaps his best role ever as Peet's cocky but likable boyfriend. Danny Glover lends dignity to the role of the tormented president. (The role originally was written for a woman, until Hillary Clinton's star began to fade during the 2008 primaries.) Chiwetel Ejiofor, as the chief scientist advising the world leaders, brings a moving sense of anguish to a stock role. Platt has fun playing the villain of the piece, and Woody Harrelson also chews the scenery as a bug-eyed radio prophet trying to warn his listeners about Armageddon. Peet's role as Cusack's ex-wife is drab, and Thandie Newton as the president's daughter has to struggle with some ponderous dialogue. But then disaster movies never have been kind to their female characters.

Cinematography, production design and visual effects are awards-worthy. Music also propels the movie, with American Idol runner-up Adam Lambert providing a rousing anthem over the end credits.