Since 2008, when the first Iron Man rocketed into the box office stratosphere, there have been eight installments in the so-called Marvel Cinematic Universe, plus the Agents of S.H.I.E.L.D. TV series.

It's a universe where Asgard and Stark Industries, the Mighty Thor and the Incredible Hulk share space, where the costumed crimefighters spawned in midcentury comic books can pull up barstools, commiserate about the burdens of fame, and strike out against common foes. A place where Marvel patriarch Stan Lee inevitably shows up in a winking cameo, and where the end credits of any given title promise new challenges to come in the next - usually in a scene with Samuel L. Jackson as the eye-patched S.H.I.E.L.D. honcho Nick Fury.

It's crossover heaven, full of synergy and mutual realities and knowing asides that make fanboys and fangirls goofy with joy.

It has also become, with each new title, more about marketing and profit sharing than about mythology and universe-sharing.

Which brings us to Captain America: The Winter Soldier, a state-of-the-art (or commerce) blunderbuss of digitally rendered aerial dogfights, kabooming fireballs, chase sequences, and battle scenes - and "serious" questions about the line where personal freedom and national security butt heads.

Sure, it's got Scarlett Johansson as the martial arts mistress and superspy Natasha Romanoff, slinked out in her Black Widow jumpsuit. And she and Steve "Cap" Rogers (the Popeye-biceped Chris Evans, back in the title role) get off some friction-force banter. Jackson, barking gruffly and conspiratorially, has a pivotal role: dispatching Captain America and the Black Widow on missions of utmost urgency, then getting gunned down (down, but is he out?) after an epic armored SUV chase on the streets of the capital.

Defrosted from his cryogenic deep-sleep at the end of 2011's World War II-set Captain America: The First Avenger, Steve Rogers finds himself in modern-day Washington, still trying to align his 1940s sense of what's-what with the head-spinning, pop-cult craziness of the new millennium. He's old-school in a new-school world, and his Boy Scout ethos doesn't sit right with drone strikes and cyber-snooping.

Natasha, a creature of the KGB, can shrug off such issues - perhaps. But not Robert Redford, that sun-burned icon of progressive liberalism, cast here as the government chieftain overseeing the ominous Project Insight and its highly weaponized "helicarrier" ships. The intrepid reporter of All the President's Men is now one of those men, wielding power in a most unconstitutional way.

The problem with Captain America: The Winter Soldier is that there's too much going on: the Marvel Universe stuff, the WikiLeaks-ish paranoia stuff, the video game-ish CG visual effects stuff, the epic John Woo-ish everybody-pointing-a-weapon-at-everybody-else face-off stuff.

When director siblings Anthony and Joe Russo get a couple of characters talking one-on-one - such as Evans' Steve Rogers and Anthony Mackie's Sam Wilson, who works with veterans and works his way into the battle sequences thanks to his wing-packed superhero alias, Falcon - the movie feels grounded in something human.

But the rest of the time - and there's a whole lot of that rest of the time - Captain America: The Winter Soldier has its boots on familiar, formulaic, Hollywood turf.

Captain America: The Winter Soldier **1/2 (Out of four stars)

Directed by Anthony Russo and Joe Russo. With Chris Evans, Scarlett Johansson, Samuel L. Jackson, Robert Redford, Anthony Mackie. Distributed by Walt Disney.

Running time: 2 hours, 16 mins.

Parent's guide: PG-13 (action, violence, adult themes).

Playing at: area theaters.EndText