After enduring more than a year of rumors and studio delays, some “Teenage Mutant Ninja Turtles” devotees may be appeased by Paramount’s fairly faithful film reboot of their beloved reptilian superheroes. But more are likely to be disappointed to discover that the talking Turtles have been reduced to sidekicks to the actual focus of this film: summer-movie sexpot Megan Fox.

The film opens with an engaging, animated prologue that retells the legend of the sewer-dwelling, genetically modified turtles and their rat sensei, Splinter (voice of Tony Shalhoub), and explains how above ground, New York City faces its biggest threat in the form of ruthless villain Shredder (Tohoru Masamune) and his menacing Foot Clan. Then it switches to 20 minutes of Fox, who as television news reporter April O’Neil desperately tries to convince her incredulous boss (Whoopi Goldberg) she’s got proof of vigilantes battling Shredder’s goons.

When April finally has her first full run-in with the mysterious crime fighters, she faints, but not before she hears the Turtles call out their Renaissance names (Leonardo, Donatello, Raphael and Michelangelo) and squeak, “She’s so hot! I can feel my shell is tightening!”

And that’s part of the problem with the movie. Although the character of April was attractive in earlier “Teenage Mutant Ninja Turtles” iterations, it’s disappointing (if predictable) that she’s overly sexualized in this installment. Mikey (Noel Fisher), he of the aroused carapace, is supposed to be smitten, but must he talk only about her hotness? Meanwhile, April’s loyal cameraman, Vern (Will Arnett), is perpetually ogling her body — even in moments of extreme peril. Maybe we shouldn’t be surprised by such fare from producer Michael Bay, but the character — not to mention young viewers of this Nickelodeon co-production — deserve better.

The film’s insistent focus on April extends to overly convenient plot points that tie her to the Turtles before their super-sized transformation. Those implausible connections lead April to reveal the existence of the Turtles to shady scientist Eric Sachs (William Fichtner, lacking only a mustache to twirl), the very man responsible for their mutation.

When the film moves past Fox to focus on the Turtles, the heroes in a half shell are undeniably impressive in ninja mode. Director Jonathan Liebesman (“Wrath of the Titans” and “Battle: Los Angeles”) knows how to highlight ILM’s performance-capture technology, which makes the Turtles’ movements so realistic. Liebesman lets the Turtles — Leo (voiced by Johnny Knoxville but played by Pete Plos­zek), Donnie (Jeremy Howard), Rapha (Alan Ritchson) and Mikey — shine as they kick, jump and parry in various large-scale action sequences. And the Turtles themselves are charming enough, even though there’s not much time invested in their personalities beyond the obvious broad strokes: Leo’s the focused leader, Donnie’s the tech genius, Rapha’s the hothead and Mikey’s the funny one who gets to shout “Cowabunga!”

Unfortunately, even during crowd-pleasing thrills, the comic relief once again circles back to the script’s favorite topic: April’s sex appeal. “Yes, that’s good,” Vern says, leering as she attempts a daredevil pose in a moving car. Perhaps the lingering shots of Fox will help young men in the audience overlook the continuity errors and sillier plot details. At one point, Sachs menacingly commands a henchman, “We’ll drain out every drop of blood, even if it kills him.” Why, yes, billionaire geneticist, that would kill him.

Considering that two sequels are in the works, it’s clear the filmmakers believe tweens and teens won’t care about the movie’s deficits and will just concentrate on the fun of wisecracking, weapon-wielding turtles (and, naturally, Fox’s hotness). And while this reboot is fun, it’s also forgettable and occasionally infuriating. 0

Chen is a freelance writer.

★ ★

PG-13. At area theaters. Contains sci-fi action violence. 101 minutes.