Ain’t no party like an ‘Avengers’ party

We already know, since Marvel announced its schedule for the next decade or two, that the third “Avengers” installment will be subtitled “Infinity War — Part One.”

But it would be just as crowd-pleasing — not to mention $200 million or so cheaper — if the studio instead went with “The Avengers: After Dark,” “The Avengers: House Party” or even “The Avengers: Pajama Jammy Jam.”

That’s because, despite the many, many (perhaps too many) action scenes, there’s simply nothing as entertaining anywhere in “Avengers: Age of Ultron” as seeing these characters we’ve gotten to know over the course of nine blockbusters as they take time to relax and unwind.

For a party at Avengers Tower, no one’s in costume. Tony Stark (Robert Downey Jr.) might as well be wearing a smoking jacket. It’s just this dysfunctional work family, including Maria Hill (Cobie Smulders), and their friends — ranging from War Machine (Don Cheadle) and Falcon (Anthony Mackie) to random World War II veterans befriended by Captain America (Chris Evans) — drinking, flirting and goofing on each other. And it’s terrific.

Although because this isn’t every other episode of “Entourage,” returning writer-director Joss Whedon decided there needed to be a plot.

“Age of Ultron” wastes about 10 seconds before the first full-on battle, with all six Avengers taking on HYDRA agents in the woods of the Eastern European nation of Sokovia.

Their teamwork has improved quite a bit since we last saw them. Most noticeably, Dr. Bruce Banner (Mark Ruffalo) has become more comfortable Hulking out, and Black Widow (Scarlett Johansson) has developed a way to soothe the savage beast. It’s our first glance at their developing romance. (While he’s Banner, that is. The alternative would be, well, ouch.)

That battle is also our first look at the Maximoff twins, Wanda (Elizabeth Olsen), aka Scarlet Witch, and Pietro (Aaron Taylor-Johnson), aka Quicksilver, whose parents were killed when Stark Industries bombs destroyed their village.

They’ve both been “enhanced,” in keeping with Marvel’s inability to utter the word “mutant,” which is wrapped up in Fox’s “X-Men” rights. Although, because of a loophole, both franchises were able to use the speedy Quicksilver. He was cooler in “X-Men: Days of Future Past,” but more integral here.

Scarlet Witch, meanwhile, is able to get inside people’s minds and make them hallucinate their worst fears. Take away her telekinesis and she just as easily could have been code-named Brown Acid.

By capturing the HYDRA research facility, the Avengers regain possession of Loki’s scepter, which Stark and Banner secretly use to jump-start the peacekeeping plan known as Ultron. “I see a suit of armor around the world,” Stark says of his program that would protect the planet from further alien invasions.

Things do not go well.

The artificial intelligence “escapes” almost instantaneously, builds himself a body out of spare robot parts and, through the smug vocal stylings of James Spader, declares war on the Avengers. The only way to protect Earth, Ultron reasons, is to rid it of superheroes.

From Stark’s Hulkbuster suit to a Wakanda shout-out, there’s plenty in “Age of Ultron” for die-hards to geek out over.

After a rash of movies where entire cities were devastated with zero regard for the human toll, it’s refreshing to see the Avengers focus on saving people one or two at a time while the fate of the world is once again at stake.

But the overstuffed finished product feels like the result of too many plot threads left on the cutting room floor. (Some reports claimed Whedon’s first cut was more than an hour longer.)

And, with the exception of one brief slow-motion scene, in which eleventy-something heroes take on four times that many robots, the big action set pieces are too jumbled to work. They’re technically proficient, but I couldn’t recall much about them on the ride home.

Thankfully, though, there are more than enough character moments to compensate.

As usual, Downey’s Stark saves the day with his flurries of asides and bons mots. But everyone involved in “Age of Ultron” earns a couple of solid laughs.

Captain America’s earnest squareness continues to make him the butt of jokes. Thor (Chris Hemsworth) is more down to Earth, literally and figuratively. And Hawkeye (Jeremy Renner) is finally fleshed out, even earning the chance to acknowledge the ridiculousness of his trying to save the planet — alongside a man in a flying metal suit, an alien god and a giant, green monster — armed with only a bow and arrow.

The Avengers, we’re told, are greater than the sum of their parts.

“Avengers: Age of Ultron” is not. But it still boasts some pretty incredible parts.

And one heck of a party.

Contact Christopher Lawrence at clawrence@reviewjournal.com. Follow him on Twitter: @life_onthecouch