If you happen to be a child of the ’80s, the odds are pretty good that you have more than a passing familiarity with the Teenage Mutant Ninja Turtles. The saga of Leonardo, Michelangelo, Donatello and Raphael – humanoid turtles mutated by radioactive ooze and trained as ninjas by their rat sensei, Splinter – began in the pages of a gritty cult comic book created by Kevin Eastman and Peter Laird in 1984. When an animated television series featuring the Turtles debuted in 1987, the reptilian quartet became immensely popular cultural icons.

The Turtles made their way to the big screen with a live-action film released in 1990. The film became one of the top five biggest blockbusters of that year, though it drew criticism for being too dark and violent for a young audience. As a result, the film’s two sequels, released in 1991 and 1993, were crafted to be lighter, brighter and more kid-friendly. They were also substantially less popular, with the third film grossing nearly $100 million less than the original.

Though the Turtles disappeared from theaters after “Turtles III” underperformed, the franchise was kept alive throughout the years in comics and cartoons, hooking new generations of Turtle fans. And now the Turtles are making their long-awaited return to multiplexes, hoping to attract children of the ’80s, ’90s and today.

The succinctly-titled “TMNT” takes our “heroes in a half shell” into the realm of CGI animation, the home of that other green superstar, Shrek. Freed from the constraints of live-action (and those cheesy rubber suits), the film is certainly flashier and more visually appealing than its cinematic predecessors.

In the original film, there is very brief, perfunctorily-shot scene of Donatello skateboarding in the sewers, with the camera primarily focused on his feet. Contrast that with the elaborate scene in the new film where Michelangelo tears through the sewer tunnels on his board, performing feats that would make Tony Hawk vomit in his mouth.

“TMNT” is not a “reboot” of the series, as “Batman Begins” and “Casino Royale” were, but is, essentially, “Teenage Mutant Ninja Turtles IV.” In the film, the Turtles’ arch-nemesis Shredder is still dead, having been crushed by a collapsing dock in the climax of the second film. His gang, the Foot Clan, is now run by the beautiful ninja warrior, Karai (voiced by “Crouching Tiger’s” Ziyi Zhang). The Foot still has unfinished business with the Turtles, but has been unable to tend to it because the Turtles have been inactive for some time.

Leonardo has been sent away on sabbatical by Splinter to the jungles of Central America, to hone his leadership abilities. With Leo away, Splinter has grounded the other three, barring them from battle until the group is whole again. While Michelangelo and Donatello pass the time by working as a children’s entertainer and a technical-support operator, Raphael has grown resentful about being sidelined by Leo’s absence, and secretly patrols the rooftops as the masked vigilante, the Nightwatcher.

The Turtles’ old buddy, April O’Neil (voiced by Sarah Michelle Gellar), is now in a relationship with the Turtles’ ally, the original masked vigilante, Casey Jones (voiced by Chris Evans). For reasons the film never explains, April is no longer a news reporter (she is also, in an odd turn, now a fully trained ninja herself), and is now employed by industrialist Max Winters (voiced by Patrick Stewart), acquiring artifacts from all around the world for him.

Winters has a secret agenda, however. He is actually a 3,000-year-old warlord who once attempted to conquer the world by opening a portal to another dimension and summoning forth a legion of monsters. When his plan was not successful, Winters was cursed with immortality and his generals were turned to stone. He now hopes to capture the 13 monsters that were released into this world to break the spell. As Leo reunites with his brothers, the foursome seeks to stop Winters.

Those Turtle fans out there who might be hoping for a return to the relative edginess of the original 1990 film will be disappointed to learn that “TMNT” is a children’s film through and through. This is not a film with an eye toward the adult (a term used loosely in this context) members of the audience, the fans who had all the toys in 1989, but are now inching up on 30. “TMNT” is an expensive, 82-minutes-long Saturday morning cartoon. Apart from a funny line where Splinter outs himself as a soap-opera fan, none of the dialogue and humor will amuse audience members who have surpassed the sixth grade.

The story is also not very interesting. Winters’ scheme to capture the monsters and end his curse never amounts to anything very compelling, or even particularly coherent. The plot unfolds in a jumble of busy scenes involving rampaging beasts, swirling clouds and blinding portals beaming up into the heavens. It’s a great deal of fast-moving action and eye-catching effects designed to keep children fixated in lieu of a watching a well-crafted story unfold.

To the film’s credit, it does make an attempt at character development, in the form of the simmering resentment between Raphael and Leonardo. Raphael is extremely bitter over his brother’s role as the team leader, and this culminates in an angry rooftop battle between the two turtles that is easily the film’s emotional high point.

The look of “TMNT” is quite good. While not up to the standards of Pixar features like “Cars” or “The Incredibles,” the film is visually enjoyable. The animation holds the audience’s interest, even though the story fails to do the same. If the film is successful, I hope the creators put more effort into the storyline for the sequel.

Near the end of the film, a hint is given that a certain razor-armored ninja might not be as dead as previously thought. Perhaps the return of an old foe will give our shell-bearing heroes a story we care about.

Brandon Wolfe can be reached at [email protected]