"Are they aliens?" news cameraman Vernon Fenwick (Will Arnett) asks when fledgling reporter April O'Neil (Megan Fox) informs him that there are a quartet of ninja-fighting vigilantes living in the NYC sewer system. "No, that would be stupid," April replies. "They're reptiles." A live-action, Michael Bay-produced 2014 reboot of "Teenage Mutant Ninja Turtles" shouldn't have any business working—setting aside any childhood nostalgia it may still carry, the 1990 film is a dismal slog—and yet, somehow, it kind of does. Based on characters created by Peter Laird and Kevin Eastman, adapted for the screen by director Jonathan Liebesman (2012's "Wrath of the Titans") and screenwriters Josh Appelbaum & Andre Nemec (2011's "Mission: Impossible - Ghost Protocol") and Evan Daugherty (2014's "Divergent"), this is high-energy entertainment well told, neither so cutesy that it becomes a chore for adults nor too violent or dark for kids. It might not stick around for long in the forefront of one's memory, but you can't always have everything when it comes to big-budget popcorn fare about mutated adolescent turtles specializing in the art of karate and eating pizza.

News Channel 6 reporter April O'Neil yearns to be taken seriously as a journalist, but instead always gets assigned fluff pieces about things like trampoline workouts. Choosing to defy the instruction of boss Bernadette Thompson (Whoopi Goldberg), she sets out to break the case on the powerful Foot Clan crime syndicate that has swept over Manhattan. It is during this investigation that she is saved by Raphael (Alan Ritchson), Michelangelo (Noel Fisher), Leonardo (Pete Ploszek, voiced by Johnny Knoxville) and Donatello (Jeremy Howard), four masked, talking, 6-ft.-tall turtles in half shells. The closer she gets to these mysterious avengers, the more their past in a laboratory—and her unexpected connection to them—comes into focus. "They were my childhood pets," April matter-of-factly says, "and they were named after Italian Renaissance painters."

"Teenage Mutant Ninja Turtles" has its campy moments and knows how over-the-top its premise is. There is no way to one-hundred percent take seriously four turtle siblings injected with a mutagen that has made them and their sage-like rat father Splinter (Danny Woodburn, voiced by Tony Shalhoub) grow to human size. And yet, as well as director Jonathan Liebesman can, he has mounted an involving story that goes back in time to explore the history of "TMNT" lore and treats all the characters with a sympathetic—or, when it comes to Foot Clan leader Shredder and duplicitous CEO Eric Sachs (William Fichtner), threatening—hand. By threading into the proceedings a meaningful link between April and the turtles—her late scientist father raised them as babies in his lab—it gives their longtime relationship an injection of heart and the reporter a fuller emotional arc.

Frequently typecast as an uncomplicated eye-candy accessory, Megan Fox (2012's "This Is 40") tackles yellow-jacketed protagonist April O'Neil as if she's got something to prove—and can you blame her? Critics and fans have been dusting off their pitchforks ever since she earned the role, and there will be some viewers who decide they dislike her before they have even watched the movie. After a bumpy introduction where, notepad and pen in hand, April not terribly convincingly tries to get an on-the-fly statement from a shipyard worker, it is all uphill for the actress. More than even the turtles, Fox is the central figure of the story, sympathetic and exhibiting fleet comic timing as a savvy, determined, go-getter heroine who shows intelligence and strength even when faced with daunting obstacles. This is Fox's best film role since 2009's Diablo Cody-scripted "Jennifer's Body," and hopefully even in this predominately silly movie producers and casting people will take notice that there is more to her than just a pretty face and hot body.

As Vernon, Will Arnett (2010's "When in Rome") is mostly along for the ride as he pines not-too-secretly for April, and William Fichtner (2013's "Elysium"), as the conniving Eric Sachs, always makes for an effective heavy. Whoopi Goldberg (2010's "For Colored Girls") runs with a couple scenes as news chief Bernadette Thompson, but she deserved a final send-off to more satisfyingly tie up her side plot with April. As for Raphael, Michelangelo, Leonardo and Donatello, they are brought to life through motion-capture technology and top-notch digital effects. While not developed with enough defining characteristics to truly individualize them beyond the colors of their respective Zorro masks, they do work as a genial unit whose ages lend themselves to a certain immaturity.

"Teenage Mutant Ninja Turtles" features not one, but two hilariously literal, overly convenient digital readouts, and returns multiple times to a perpetually snowy location that is supposedly an hour outside of a powder-free, barely chilly NYC. Meanwhile, the pop-culture-loving turtles aren't above a few of their old one-liner-spouting antics and a sing-along to Gwen Stefani's "Hollaback Girl." The film alternates between tongue-in-cheek winks and, quite possibly, a few IQ lapses, but it is easy to forgive its most preposterous elements with this already-silly property. When the full scope of Shredder's malevolent plan is unraveled, the film takes off for a final act that delivers at least two action setpieces—one involving big rigs, jeeps, SUVs and snowboarding turtles on a cliffside mountain, and the other taking place high above Times Square—which rank as some of the most legitimately thrilling, cohesively edited of the whole summer. In spite of the movie's shortcomings, there is an eager-to-please quality to the whole of "Teenage Mutant Ninja Turtles" that is difficult to resist.