Here’s a question: Why do the Ninja Turtles wear masks? What could they possibly have to hide? Are they worried people will discover their secret identities as mutant turtles who work day jobs as, like, electricians or tech support?

This is the sort of thing one thinks about while watching Teenage Mutant Ninja Turtles: Out of the Shadows because there's not much else to think about. True, Out of the Shadows is an improvement over the last Ninja Turtles movie, but only in the way that a mild cold is an improvement over the flu. It’s not good, but at least it’s not so terrible that it makes you want to lie in bed for a few days.

2014’s Teenage Mutant Ninja Turtles, the first live-action reboot produced by Michael Bay and his Platinum Dunes company, tried a more serious approach to the material. That was a mistake. The concept of reptiles transformed by scientific meddling into wise-cracking muscle-bound superheroes demands as much seriousness as a convention of Whoopee cushion manufacturers. Out of the Shadows at least corrects that error by embracing the series’ colorful side. As directed by Dave Green, it brings in the old Turtles cartoon’s bumbling mutated henchmen, Bebop and Rocksteady (Gary Anthony Williams and WWE wrestler Sheamus). It introduces Krang (Brad Garrett), a talking, tentacled brain from another dimension who wants to conquer the Earth. And it lets the Turtles themselves tell jokes and watch Knicks games and have a little fun when they’re not moping around in the sewers. The way the characters and storylines are integrated don’t always make sense, but at least this movie knows what it is and it owns it.

What melodrama and unwelcome grittiness remains in the sequel involves the sewers, which are as much the Turtles’ home as their self-imposed prison. Afraid of what society might do if they discovered a bunch of mutant crime fighters in their midst, they stick to the shadows, dreaming of a day when they could live their lives cowabungal fresco. Of course, the Ninja Turtles’ idea of hiding in the shadows involves driving down busy highways in the stealthiest of vehicles: A tricked-out garbage truck that shoots manhole covers and has giant robot arms (with giant robot nunchucks). No one would ever notice that!

While the Turtles themselves are pretty entertaining, with a strong familial rapport, most of Out of the Shadows’ plot proceeds this way; that is to say, nonsensically. April O’Neal (Megan Fox), the Turtles’ one human ally, is apparently still a reporter, although she never goes to an office, or files any reports until the very last scene of the movie, and she’s investigating a mad scientist named Baxter Stockman (Tyler Perry, who looks like he's having a lot of fun). Stockman works for Shredder (Brian Tee), and creates a teleporter to help him escape police custody. But somehow the device misfires and sends Shredder to Krang’s dimension, where the disembodied brain orders him to return to Earth to retrieve some pointless glowing MacGuffins to facilitate his plan to conquer the world.

Two of these MacGuffins are in New York, but the third is randomly in a Brazilian rainforest, which necessitates the Turtles (who, again, live in secret and cannot be seen by anyone) hopping a plane to South America. There's no reason for the entire movie to stop so everyone can relocate to Brazil except to shoehorn in an elaborate action scene that spills out of this setup involving the Turtles skydiving between planes. It’s as if the setpiece was conceived before its motivation, and then screenwriters Josh Appelbaum and Andre Nemec were ordered to create a flimsy plot contrivance to get the Turtles onto the cargo jet in the first place.

Stephen Amell exudes a likable, wholesome vibe as Casey Jones, an NYPD corrections officer turned hockey-themed vigilante, and Megan Fox has a couple amusing moments working “undercover” as April. It is interesting to note, though, how much time these characters spend away from Leonardo and company. Though this is ostensibly a “live-action” Teenage Mutant Ninja Turtles, the human actors and the digital ones remain separated in parallel plots; the Turtles are mostly in all-CGI adventures (like the plane-to-plane skydiving sequence) while Amell and Fox get interrogated by three-time Academy Award nominee Laura Linney as high-ranking New York cop. (Something tells me this role won’t net Linney that fourth Oscar nom.)

The cutting back and forth from the mundane to the surreal makes it even more apparent just how cruddy these motion-captured Turtles look. If they’re going to be digital characters fighting digital monsters in a digital fortress in the digital sky for the sake of a digital city, why not just make a cartoon? The Turtles’ quest to step out into the sun dovetails with the movie’s meta-narrative about owning the inherent goofiness in the Ninja Turtles concept. But while the characters feel much more comfortable in outlandish environs, their CGI avatars looked a lot better in the dark. Maybe that’s why they wear the masks.