The Teenage Mutant Ninja Turtle franchise, sometimes abbreviated as TMNT, ought be rated FFO – For Fans Only. Everything normally considered a drawback in a movie, such as the grating characters and the rickety plots, seem to be exactly what loyal fans want.

“Teenage Mutant Ninja Turtles: Out of the Shadows,” a sequel to the 2014 film that re-launched this comic-book property, ought to please the mostly young crowd at which it’s aimed. It’s another loud, garish movie brightened by a few slick action sequences, an authentic New York City backdrop (kudos on both counts to director Dave Green) and an unexpectedly fun Tyler Perry as a mad scientist. Like the first film, “Out of the Shadows” is basically junk food, no better or worse for your children than a tub of popcorn and a keg-sized Coke.

Once again, our four reptilian heroes — team leader Leonardo (Pete Ploszek, providing his own voice this time), rebellious Raphael (Alan Ritchson), tech-geek Donatello (Jeremy Howard) and sweet-natured Michelangelo (Noel Fisher) — are distinguishable mostly by their little color-coded bandito masks. Only intrepid television reporter April O’Neill (Megan Fox, showing skin and batting lashes) and her cameraman, Vern (Will Arnett), can tell the turtles apart with ease. Joining their group is a human newcomer, Casey Jones (a likeable Stephen Amell), whose unusual weapon of choice is a hockey stick.

The plot? Boy, that’s complicated. The arch-villain Shredder (Brian Tee, replacing Tohoru Masamune) teams up with the evil Dr. Baxter Stockton (Perry, with giant glasses and a goofy giggle) to create one of those space-time portals that lets in aliens. The real villain is Krang, a wet tangle of organs and brains with the spluttering voice of Brad Garrett. Gary Anthony Williams and pro wrestler Stephen Farrelly, as thugs transformed into animals (don’t ask), provide some enjoyable buffoonery.

There’s no getting around the fact that “Out of the Shadows” is one ugly-looking movie, filmed mostly in the eerie greens and reds of an old black-light poster. The turtles themselves remain unattractive motion-capture creations with splotchy skin, human teeth and no lips, while their master, a scraggly rat named Splinter (the voice of Tony Shalhoub), isn’t any prettier. For fans, of course, that’s all good news.