The characters in current superhero movies must’ve grown up reading comic books.

The characters in current superhero movies must’ve grown up reading comic books. In Marvel’s run of blockbusters, Iron Man and Thor and the gang (well, maybe not Captain America) are steeped in cultural references; they know all the cliches of pulp fiction, even as they embody them. Aware of the absurdity of wearing tights and wielding magical hammers, they make jovial banter about it when they’re not busy saving the world. This self-conscious tendency reached its peak in Guardians of the Galaxy, a stealth-bomber sendup of the superhero movie.

Avengers: Age of Ultron can’t top Guardians in that department. But writer/director Joss Whedon balances comedy and derring-do with dexterity, and this sequel to 2012’s top grosser doesn’t stall the franchise. Plus it’s got new characters to geek out about, villains especially. Ultron is an artificial-intelligence “murderbot” inadvertently created by billionaire Tony Stark (Robert Downey, Jr.)—also known as Iron Man, of course—and scientist Bruce Banner (Mark Ruffalo), aka the Hulk. Ultron changes robotic shape during the film, but his voice is provided by James Spader, who sounds like a tiger mellowed out on expensive brandy. He’s fun, if perhaps overly humorous for a creature who seeks to end mankind’s dominance on Earth. But Whedon, an encyclopedia of pop culture, can’t help himself—earnestness about this nonsense is for 20th-century suckers.

The Avengers must fight Ultron as well as newcomers Quicksilver (Aaron Taylor-Johnson) and Scarlet Witch (Elizabeth Olsen). Paul Bettany, previously the voice of Tony Stark’s computer, gets an expanded role here, and makes something haunting out of it. It’s a crowded field, although Whedon tries to find bits and bobs for everybody. Except Thor (Chris Hemsworth). Even Whedon can’t really make Thor very interesting. What gave The Avengers its kick was the recognizably human interplay between these titans, and on that score Ultron falls down a little: The rivalry between Stark and Steve Rogers (aka Captain America, played by Chris Evans) isn’t fresh; the heat between Banner and Natasha Romanoff (aka Black Widow, played by Scarlet Johansson) feels obligatory; and the backstory for Hawkeye (Jeremy Renner) is a standard attempt to provide “depth” for one-dimensional characters.

Still, it’s possible to approve of how such a billion-dollar apparatus can be this fast and breezy. And—as though Whedon absorbed some of the criticism of the first film’s endless climax, in which countless citizens must have perished while the superheroes cracked wise—the big finish here isn’t as bloated. Even Marvel skeptics have Ultron to enjoy. It’s not easy to out-irony Robert Downey, Jr., but Spader succeeds; Ultron wouldn’t be out of place as a campy Austin Powers villain. “I’m glad you asked that,” says Ultron in response to one of Stark’s questions. “Because I wanted to take this time to explain my evil plan.” He then destroys everything in sight.

film@seattleweekly.com

AVENGERS: AGE OF ULTRON Opens Fri., May 1 at Cinerama, Sundance, Ark Lodge, Majestic Bay, Kirkland, Bainbridge, and other theaters. Rated PG-13. 141 minutes.