The film opens on the Autobots' home planet of Cybertron, where they're promptly forced to retreat. One of the soldiers, B-127, is dispatched to Earth, hoping to prepare it for his brethren — and not incidentally, thwart any evil Decepticons that might follow him there.In the movie's clunkiest twist, the yellow fellow initially crashes among a group of government operatives, led by the hard-charging Agent Jack Burns (John Cena). It's mostly an excuse for a big action sequence before the movie segues into a lower-key mode, after the Autobot soon to be christened Bumblebee is taken in by Charlie Watson (Hailee Steinfeld), a just-turned-18-year-old desperate for a car, even if it's a beat-up Volkswagen Beetle.Still grieving over her father's death, Charlie is very much in need of a pal to shake her out of her funk. Like Elliott in "E.T. the Extra-Terrestrial," she must conceal Bumblebee from her mom (Pamela Adlon, odd casting that), while learning to communicate with her new ride, who uses song snippets to respond.The "E.T." reference is perhaps too charitable, since "Bumblebee" is just as much a mechanized "Mighty Joe Young." The net effect, though, is to set up an us-against-the-world dynamic, creating an excuse for Charlie to bond with the nerdy neighbor (Jorge Lendeborg Jr.), who, until this new development, struggles to muster the courage to speak to her.Notably, director Travis Knight is an animation veteran, whose credits include "Kubo and the Two Strings" and (as a producer) "The Boxtrolls." "Bumblebee" definitely has a more family-friendly feel, which doesn't mean there's not plenty of action involving giant mechanized warriors beating the oil out of each other.Most happily, the movie (written by Christina Hodson) proves disarmingly witty, working "The Breakfast Club" into its shtick, referencing the Cold War not long before the Berlin Wall comes tumbling down and indulging in teen hijinks — like toilet-papering a house — that Bumblebee embraces with a little too much gusto.Admittedly, some of this praise comes from a place of utter skepticism with a five-film franchise that — under the stewardship of director Michael Bay — is a sort-of poster child for empty-headed blockbusters that play well internationally because explosions are a universal language and the dialogue's mostly irrelevant anyway.The production notes refer to this as a "kinder, gentler" take on "Transformers," which sounds better than a "quieter, less irritating" one.Even grading on a curve, though, this is a solidly executed story, tapping the familiar theme of a troubled kid whose life is changed by an extraordinary visitor. And it's grounded in reality thanks to Steinfeld, a budding star basically reprising the character she played in the indie film, "The Edge of Seventeen," only with a lot more destruction of property.Joining a movie series that has consistently added up to less, creatively speaking, than the sum of its parts, for once there really is more to "Bumblebee" than meets the eye."Bumblebee" premieres December 21 in the United States. It's rated PG-13.