Cooley, Josh

An animated prequel maps out a tidy mythology while indulging in the toy-smashing thrills of the ’80s cartoons.When settling into “Transformers One,” the latest spinoff of the alien robot franchise, you may have a pang of nostalgia for what suddenly feels like the quaint mayhem of Michael Bay’s original film from 2007.Back then, “Transformers” was about as much of a ludicrous commercial tent pole as you could come up with: Bayhem unleashed on a Hasbro toy. The franchise that film spawned has managed to extend its life force well into a movie era defined by intellectual property equations. Say what you will about Bay’s metal masher, but it was, in its early goings, a blockbuster that had its own ethos. Now, 17 years later, we’re down to an animated prequel for kids.This is all what a cynic may think at the start of “Transformers One.” But by the end, the film offers a different kind of nostalgia, one that harks back to and indulges the toy-smashing thrills that an ’80s kid would get from a dose of the original animated cartoons.This movie, directed by Josh Cooley, scraps everything we associate with its cinematic forebears and goes back to the beginning, creating, on a structural level, an effective origin story of the Transformers universe.Before Optimus Prime (Chris Hemsworth) and Megatron (Brian Tyree Henry) were enemies, they were best friends and young nobodies, two miners toiling away as part of an underclass that provided the energy for the planet of Cybertron.But after unwittingly finding a clue to the long-lost Matrix of Leadership, the vital key to the their world’s energy, they, along with Elita-1 (Scarlett Johansson) and a young Bumblebee (Keegan-Michael Key), embark on an adventure and uncover a conspiracy that shifts both the fabric of the planet and of their friendship.It’s a completist piece of lore-building that is sturdily developed but frequently includes stiffly explicative dialogue; Hemsworth and Johansson don’t help much, though Henry gives us a believable transformation into villainy and Key is dexterous comic relief. The missteps can be forgiven and even feel somewhat appropriate when it becomes clear just what kind of itch the film means to scratch: to plot out an immersive mythology in order to have some pulpy fun.That philosophy may explain the film’s confounding computer-generated style — one that can have a rich Cybertron universe but also can revert to what feels like a B-rate children’s TV spinoff. The result is a blockbuster animation film that somehow reads both very expensive and inexplicably cheap.Will fans care all that much, though? Most palpable in its frames are the heart and genuine love for this universe, and when the bots start colliding, with action sequences toward the end that are thrillingly punchy, it’s easy to surrender to the lore. In this way, Cooley’s film makes a good spinoff suddenly seem simple: Sometimes all you need is the imagination for heroes and villains, betrayal and glory — and heaps of plastic to smash together.Transformers OneRated PG. Running time: 1 hour 44 minutes. In theaters. More