Ninja Turtles get seriously animated

In the age of “Batman Begins” and “Superman Returns,” the hatchers of the Teenage Mutant Ninja Turtles franchise must have seen a promising opportunity to re-imagine their heroes for a new generation. Toward that end, “TMNT” bids farewell to the jokey, cheesy guys-in-rubber-suits world of the ‘90s movies in favor of a more character-oriented approach, a grittier look and superb computer animation -- with decidedly mixed results.

This installment finds the reptilian crime fighters idling as they wait for anointed leader Michelangelo to complete the training for which sensei Splinter has sent him away. Rebellious Raphael, however, is secretly moonlighting as an armored vigilante and building resentment toward his absent brother. The team reunites in time to contend with an immortal warlord and his stone generals, who are collecting monsters to open a Ghostbuster-ish cosmic portal.

“TMNT” features an impressive collection of voice talent, led by Patrick Stewart as a mysterious industrialist, Ziyi Zhang as the leader of the rival ninjas and the late Mako as Splinter, the turtles’ rat “father.” By the way, Splinter is now cuddly. The detail in the movement and color of his fur makes him the cutest human-sized sewer rat you’ll ever see.

“Shrek” and “The Incredibles” may have raised the animation bar, but the texture in the costumes and the turtles’ skin, even in the way distinct raindrops splash and dissipate on characters’ faces, stands up to comparison. The gloomy city backgrounds are beautifully rendered, and the villain and monster design is excellent. The stone generals look like something right out of comic god Jack Kirby’s feverish dreams.

Alas, these turtles are not so happy together. The family-schism subplot involving Leonardo (James Arnold Taylor) and Raphael (Nolan North) seems wedged in for gravitas, but all it does is weigh the movie down. It also reminds us of the all-too-obvious X-Men parallels: Leonardo as the ho-hum Cyclops analogue and Raphael as a poor man’s Wolverine, without the humor.

That’s really what “TMNT” lacks most -- humor. Despite the doll-like cartoonishness of the human figures (O Pixar, what hast thou wrought?), the filmmakers seem to expect us to take this animated romp seriously. Too seriously. More of good-naturedly dimwitted, skateboarding brother Michelangelo (Mikey Kelley) with his “cowabungas” and surfer-dude idiocy would have been welcome.

Fans of the comic book may disagree, but a franchise that began as a parody of superheroes doesn’t seem suited to the serious approach.

“TMNT.” MPAA rating: PG for animated action violence, some scary cartoon images and mild language. Running time: 1 hour, 30 minutes. In general release.