
 
 The Avengers reunite to take on a new enemy: a silky-voiced, ember-eyed robot named Ultron, played with characteristic suaveness by James Spader. (Marvel/Walt Disney Studios) 
 
 ‘We’re mad scientists, monsters. You gotta own it.” That’s Tony Stark lecturing his partner in ­world-saving, Bruce Banner, while fooling around with a little ­sentience-integration work in the lab in “Avengers: Age of Ultron.” As the second installment of the Marvel Comics-based series that began in 2012, “Age of Ultron” seeks mightily to portray its core group of superheroes as misfits and antiheroes, haunted by their own compromised pasts and emotional shadow material. 
 
 The fact that “Age of Ultron” only partially succeeds at that mission is actually a good thing. As he did in the first “Avengers,” writer-director Joss Whedon avoids the fatal trap of comic-book ­self-seriousness, leavening a baggy, busy, overpopulated story with zippy one-liners, quippy asides and an overarching tone of jaunty good fun. There are plenty of blockbusters these days that feature a noisy, protracted, risibly improbable motorcycle chase; “Age of Ultron” may be the first in which the driver delivers a cheerful “beep-beep!” as she’s plowing through pedestrian traffic. 
 
 [Summer Movie Guide: Popcorn flicks with a sprinkling of nostalgia] 
 
 It’s just that chirpy, unpretentious tone that sets Whedon’s “Avengers” apart from the superhero pack, and that barely saves “Age of Ultron” from collapsing under its own overdetermined weight. There are great swaths of this movie that viewers may never understand. (Where exactly does the Hulk go when he disappears for minutes on end?) And like so many examples of the genre, this sequel suffers from repetitive, too-long action sequences and the utterly useless cash-grab of 3-D. The draw here is the band that’s getting back together, as Captain America, Iron Man, Thor, the Hulk, Hawkeye and Black Widow recapture the prickly chemistry that makes them click. The novelty lies in watching them dispatch yet a brand new villain: in this case the title character, a silky-voiced, ember-eyed robot, played with characteristic suaveness by James Spader. 
 
 [Just how many records can this hulked-out sequel smash?] 
 
 Before he shows up, though, fans are treated to a reprise of what made the first “Avengers” such a blast: “Age of Ultron” begins in the midst of a by-the-numbers battle in which the team members show off their individual strengths (a tableau that will be recapitulated in a third-act donnybrook that plays like a greatest hits medley). But the real fun starts when the group gets together for a party at Stark’s Manhattan penthouse, and the patter starts pinging. While Tony/Iron Man (Robert Downey Jr.) and Thor (Chris Hemsworth) spar about their absent girlfriends, Bruce/Hulk (Mark Ruffalo) and Natasha/Black Widow (Scarlett Johansson) exchange meaningful glances at the bar. Later, Thor challenges all comers to see if they can lift his Asgardian hammer, as magnificently overcompensating a phallic symbol as it sounds. 
 
 Ultron returns to cause even more trouble for the heroes in another trailer for Marvel's "Avengers: Age of Ultron," in theaters May 1. (Walt Disney Pictures) 
 
 It’s all terribly silly. (“None of this makes any sense,” says Jeremy Renner’s Hawkeye at one point.) And Whedon and his cast make few apologies for that fact. Rather, they lean into the outsize feelings and gestures with a combination of goofy humor and utterly sober and convincing focus on their individual characters’ anxieties and motivations. All of them have secrets and issues to work out — the most tortured being Ruffalo’s quiet, mournful Bruce Banner — and they come distressingly into play when the group meets a pair of Slavic twins portrayed by Aaron ­Taylor-Johnson and Elizabeth Olsen, the latter of whom plays a dazed-looking spellbinder with a gift for mind games. 
 
 For all the troubled doors Olsen’s character opens for the protagonists, however, Whedon never lets the dark stuff overwhelm the easygoing, even warm atmosphere he’s set up, whether by way of that little “beep-beep” Natasha delivers on her motorcycle or Tony Stark compulsively referencing everything from graffiti artist Banksy to Eugene O’Neill to Yahtzee. 
 
 Stark, of course, is the most obnoxious of the Avengers, a wealthy, cock-of-the-walk embodiment of entitlement and arrogance who’s just begging to be taken down several notches. He meets his match, knowing wink for knowing wink, in Ultron, a character that’s tailor-made for Spader’s late-career incarnation as the smooth, erudite baddie who’s so easy to loathe. The battle of wits between the two ultimately pivots around issues of super-ego and id, pluralism and chauvinism, chaos and order. They’re noble, even poetic sentiments — especially when they’re engaged by Paul Bettany’s Jarvis, who assumes a gratifyingly central and expressive role here — but they’re nearly drowned out in battle scenes that reduce the entire world to a dusty, shredded pulp. 
 
 Whedon stages the literally earth-shattering mayhem with impressive commitment, but the inevitable computer-generated apocalypse has begun to look tiresomely standard-issue by now. No one will leave “Age of Ultron” breathlessly analyzing how the filmmakers staged a disastrous earthquake in a fictional Eastern European country, any more than they’ll be talking about redundant set pieces involving robot armies and last-ditch rescues. They’ll be talking about Stark’s ever-reliable bravado; Bruce’s solitary psychic journey; whether the enormous green ­rage-monster and Natasha will ever get together and — most important, for the Marvel franchise — whether the handful of new characters introduced in “Age of Ultron” can hold their own with this flawlessly well-tuned ensemble. Casting has been a crucial element in the “Avengers” formula, and once again Whedon has enlisted surpassingly gifted actors to inhabit an ever-widening shared universe. He’s wise enough to know that these funny, conflicted, deeply pained characters are never more human than when they’re at their most monstrous. ||||| Those truly committed to the Kremlinology of Marvel Comics will find “Avengers: Age of Ultron” a revelatory piece of 3-D entertainment. Who knew that the evil Baron von Strucker (Thomas Kretschmann) had been working on the kind of robotics that would provide superhero/industrialist Tony Stark, also known as Iron Man (Robert Downey Jr.), the groundwork for developing an artificial intelligence that could threaten the existence of all human life on Earth? Who knew The Incredible Hulk could be a romantic lead? 
 
 For those... ||||| How can you expand a cinematic universe of hit after hit? With another hit. From the very first word in the new Avengers blockbuster, you know you’re in for a Mach 5 roller-coaster ride, with many stops at Ferris wheels, bumper cars, water slides and merry-go-rounds. 
 
 “The Avengers: Age of Ultron,” an industrial-powered Marvel/Disney entertainment behemoth piloted by writer/director Joss Whedon, starts with a hello that Uncle Walt and Stan Lee would never approve, and that’s the first shot in a barrage of clever, naughty, moving, inventive ideas fired at Gatling-gun speed. It feels as if this comic book franchise has become a never-ending cinema story. If future films are as well realized as “Ultron,” that’s fine by me. 
 
 Whedon, equally good at action spectacle and solid narrative, begins in the middle of things. Without a tweet of setup we launch into an extended battle extravaganza following individual Avengers, duo teams, and all six united to clobber an evil HYDRA army in a European forest. There’s the Black Widow (Scarlett Johansson), partnering with Bruce Banner’s Hulk (Mark Ruffalo). Archery whiz Hawkeye (Jeremy Renner) fires his bow as fast as the hammer of Thor (Chris Hemsworth). Captain America (Chris Evans) races through the combat on his supersonic motorcycle as Tony Stark (Robert Downey Jr.) strafes from the skies in his Iron Man armor. 
 
 It’s a blissfully realized blitzkrieg, presented with full confidence that we already understand these characters, enjoy elegant production design, and dislike needless exposition. It’s also a master class in how to launch viewer interest and delight. 
 
 With the villains brought down and their home base in mythical Sokovia emptied, the group moves ahead as Downey’s preening egotist thinks they should, to a gala party in his Manhattan penthouse. It’s a chance to let audiences breathe and let the cast act. 
 
 The previous film introduced these once-independent superhero stars as strangers wrestling with their resentments of each other while trying to tackle their external enemies. Here, they’re relaxed and celebratory, with plenty of laughs (this film contains a remarkably good series of gags about Thor’s magical mallet). 
 
 Banner and the Black Widow are progressing beyond a close friendship. She so effectively talks him down from his green attack mode with her “Hey, big guy” lullabies that they are moving toward, wonder of wonders, a potential romance. Which in time triggers a priceless Iron Man zucchini joke that is only barely PG-13. 
 
 It’s part of Whedon’s signature balancing act between racing, hitting and shooting, and heartfelt human interaction. In his 2012 smash “The Avengers,” he rescued the problematic character of the Hulk by focusing on Banner’s emotional anguish and his alter ego’s Tasmanian Devil comic violence. Here he pushes Hawkeye beyond his near-cameo in earlier films with a look at the life and values and family the archer has on his own. Whedon doesn’t focus so much on explosions that we lose track of the human heart. His film and TV projects outperform his competitors’ because he allows us to learn and care about the players. 
 
 And sometimes to dislike them. For his victory prize, narcissistic weapons designer Stark devises an artificially intelligent shield to defend Earth from alien attack. The plan is a pompous take on a valuable principle. Instead of inventing a guardian, Stark creates the robotic title character, the biggest, baddest comic book villain in a million, bazillion, infinity years. 
 
 Voiced by James Spader, Ultron is also the most sarcastic. He explains that he sees his mission as destroying the Avengers and humanity itself, then coasts into Pinocchio’s “I’ve Got No Strings.” Who but Whedon could imagine this cheerful Disney charmer in the key of doom: “I’ve got no strings / To hold me down / To make me fret, or make me frown / I had strings / But now I’m free / There are no strings on me.” 
 
 Ultron can’t wait to kill his Geppetto father figure, since the poisoned apple falls close to the sour tree. He quickly drafts allies in Wanda (Elizabeth Olsen) and Pietro Maximoff (Aaron Taylor-Johnson), super-powered Sokovian twins whose parents were killed a decade earlier by Stark-brand bombshells. Wanda’s abilities let her push each Avenger into paranoia by triggering their individual nightmares — Stark imagining giant mechanical electric eels, Thor visiting Asgard’s dancing dead. 
 
 The film gives much of its attention to the team’s efforts to hold onto their loyalty, now that the institution of S.H.I.E.L.D. has been decimated and their small corps faces attacks designed to break them apart. It builds to a bombastic finale, a limitless overstuffed smorgasbord of sky-high battle. It works, where Michael Bay’s pointless Transformers films and Zack Snyder’s disappointing “Man of Steel” stumbled. First, Whedon avoids cutting so fast that the fireballs, falling buildings and smashed cars feel like outtakes from a demolition derby. More important, his warriors prize saving the civilians. A large part of the climax derring-do is about rescuing humans, a heartening, hero-cheering notion. 
 
 This chapter has already picked up more than $200 million from the world box office before its U.S. opening, and seems set to break $1 billion soon. I bet we’ll be seeing a few more. 
 
 colin.covert@startribune.com • 612-673-7186
– The superheroes are back for round two in Avengers: Age of Ultron, following 2012's well-reviewed original. If you're expecting just another action flick, you may be in for a surprise. Here's what critics are saying: "As he did in the first Avengers, writer-director Joss Whedon avoids the fatal trap of comic-book ­self-seriousness, leavening a baggy, busy, overpopulated story with zippy one-liners, quippy asides, and an overarching tone of jaunty good fun," writes Ann Hornaday at the Washington Post. There are "repetitive, too-long action sequences," but the "flawlessly well-tuned ensemble" of characters are well worth watching. Steven Rea at the Philadelphia Inquirer agrees the best of the movie is showcased in the "quieter moments," when the screenplay's humor comes alive. The theme of the flick is teamwork, but the movie is missing "a sense of spontaneity" because of all the filming in front of green screens and with body doubles, Rea says. "As the franchise thunders on, it's also becoming more and more a bore." "For those more concerned with what the Avengers movies do best—outsize spectacle and wry comedy—Age of Ultron has to be declared a victory," John Anderson writes at the Wall Street Journal. Though its predecessor was often "bogged down by narrative baggage," this flick is more "buoyant" and "pretty amusing." A warning, though: the 3D is nothing special, Anderson notes, adding that a scene of a falling Manhattan skyscraper is "beyond tasteless." None of that seems to bother Colin Covert at the Minneapolis Star-Tribune. "If future films are as well realized as Ultron, that’s fine by me," he writes. Viewers can laugh along with "a remarkably good series of gags about Thor's magical mallet" as the movie "builds to a bombastic finale, a limitless overstuffed smorgasbord of sky-high battle. It works, where Michael Bay's pointless Transformers films and Zack Snyder's disappointing Man of Steel stumbled."