Joss Whedon's highly anticipated “Avengers: Age of Ultron” boasts perhaps the biggest bunch of superheroes yet.

And Whedon is excellent at illustrating the conundrum central to superhero moves, exploiting what makes them so popular to the masses: In everyday life, we're awkward and uncertain, but each of us just might have some kind of secret power that helps us feel stronger. The drama of the best superhero stories stems from the notion that these sides are always in conflict.

In addition, Whedon is highly skilled at creating ensemble pieces, and giving each character weight. He also writes good dialogue, creates smart, striking action scenes and keeps up the pace.

In short, he's a super-juggler. But on “Age of Ultron,” he seems to have lost control of some of the balls. The new movie succeeds, but falls short of his incredible achievement on 2012’s “The Avengers.”

“Ultron” begins with our team — Iron Man (Robert Downey Jr.), Thor (Chris Hemsworth), Captain America (Chris Evans), Hulk (Mark Ruffalo), Black Widow (Scarlett Johansson) and Hawkeye (Jeremy Renner) — retrieving part of Loki's scepter and battling super-powered twins Quicksilver (Aaron Taylor-Johnson) and Scarlet Witch (Elizabeth Olsen).

Tony Stark (aka Iron Man) and Bruce Banner (aka Hulk) decide to use the scepter to build artificial intelligence that can help protect the earth. That doesn’t happen. Instead, Ultron (James Spader), a megalomaniacal robot that wants to save the world by destroying it, enters the scene.

Although “Ultron” has huge, slam-bang battles – in which cars, bridges and buildings are destroyed and chunks of rock and metal are flung far and wide – its best parts are when the characters face their own emotional foibles. For example, Scarlet Witch has the power to make people experience their own worst fears like a nightmare; for awhile, that shakes up the heroes.

The movie also plays with themes of connections and bonds, such as twin siblings, a secret family, and even the sweet beginnings of a crush between two heroes. Whedon is good at portraying small moments, showing the characters flirting and messing around. And his running jokes about bad language and lifting Thor's hammer are delightful.

But no mortal man can be in charge of this many superheroes and not lose focus. The characters’ interactions begin to feel timed rather than natural, and battles fall out of rhythm.

Still, it’s not a total loss. Whedon, who brings his own personality to “Avengers: Age of Ultron,” clearly cares, and he’s made a movie worth watching.

REVIEW

Avengers: Age of Ultron

Three stars

Starring: Robert Downey Jr., Chris Hemsworth, Chris Evans, Scarlett Johansson

Written and directed by: Joss Whedon

Rated PG-13

Running time: 2 hours, 21 minutes

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