"Titan A.E." is an imaginative, highly ambitious animated science fiction yarn. Aside from the characters, almost everything in the film is computer animated, which puts it in direct competition with Disney's "Dinosaur" for most awe-inspiring visual prowess in an animated film. While "Dinosaur" has a more textured, three-dimensional feel to it, "Titan A.E." is still the more visually inventive of the two films, perhaps because it has the entire universe as its canvas.

Directors Don Bluth and Gary Goldman, who last worked together on "Anastasia" (1997), use this canvas well, imagining distant worlds adrift in infinite space that is not a dull vacuum, but an intensely colorful place of rotating nebulas, fiery suns, and mazes of monstrous, jagged ice formations. Perhaps the greatest visual achievement in "Titan A.E." is its elaborate reworking of outer space, which in most science fiction films is simply a black void that must be traversed in order to get to other planets.

The film takes place at the beginning of the 31st century. The "A.E." part of the title stands for "After Earth" because, in the film's eye-popping opening sequence, the Drej, a race of wicked aliens composed of pure energy, destroy Earth because they fear humankind's latest invention, the Titan Project. Fast forward 15 years, and the film's hero, Cale (voiced by Matt Damon), is one of the few surviving humans still adrift in the cosmos. Most humans live in "drifter colonies," but Cale prefers to keep to himself, working with aliens at an interstellar scrap yard. Cale's father was the chief designer of the Titan Project, and he feels that his father deserted him during the Drej attack on Earth.

One day, Cale is approached by Korso (Bill Pullman), a ship captain who knew Cale's father. Korso believes that the Titan Project is the key to saving the human race from extinction, and he needs Cale because Cale has a ring given to him by his father that contains a map to where the Titan is hidden. So, the film becomes a race to find the spaceship before the Drej find it and destroy it.

On a visual scale, "Titan A.E." is a wonder. It is not only inventive in its animation, but in its camera movements and framing. This is a highly kinetic film, and there is never a dull moment; each frame is filled with a wealth of striking visual detail. Co-director Don Bluth is one of the most visually expressive animation directors around; his 1982 film "The Secret of NIHM" is still one of the best animated films ever made. With "Titan A.E.," Bluth has at his fingertips the technological capability to render almost anything on-screen, and he leaves little to the imagination.

Unfortunately, like so many films of late, all of film's visual extravagance comes at the expense of story and characters. The script for "Titan A.E.," which was penned by three screenwriters--including John August ("Go") and Joss Whedon ("Toy Story," "X-Men")--is functional at best; it seems busy and inspired at first, but it feels less and less original as the story wears on. "Titan A.E." is the obvious descendent of many sci-fi films. Its narrative inspiration from "Star Wars" (1977) is readily apparent, some of its rock'n'roll sensibilities are derived from "Heavy Metal" (1981), and the long sequence in which Cale's ship plays hide-and-seek from an enemy ship in the Ice Rings of Tigrin seems directly inspired by a similar sequence in "Star Trek II: The Wrath of Khan" (1982) that took place in a maze of nebulous space clouds.

The main characters are serviceable, with big name marquee stars like Matt Damon and Drew Barrymore (who voices Cale's love-interest, a feisty pilot named Akima) making little impact. They fill the soundtrack with their familiar voices, but they don't make the characters particularly interesting or worth caring about. Some of the secondary characters are more memorable, such as John Leguizamo's Gune, a big-eyed, toad-like creature who is the scientist/navigator of Korso's ship, and Nathan Lane's Preed, Korso's smarmy, reptilian, first mate.

Still, "Titan A.E." has enough moments of pure spectacle to keep the viewer's interest, even if the characters don't. The movie's strength is its visual inventiveness and its daring; the medium of animation allows the filmmakers free reign in a way that even the best live-action filmmaking cannot replicate (although George Lucas tried his best with "The Phantom Menace").

The film does stumble from time to time; when the soundtrack starts blaring forgettable alternative rock songs that comment clumsily on the action (the worst example being when Cale gets to fly Korso's ship for the first time, with the soundtrack blaring "It's My Turn to Fly"), the film takes on a distinct tone of pandering to its audience. Moments like these suggest that the filmmakers are just trying to fill time until the next action sequence. Luckily for the audience, those action sequences are worth waiting for.