Mickey Rourke and Robert Downey Jr. are fascinating actors in such radically different ways that you wonder what it would be like if they made a movie together. You'll still be wondering after watching [movie id="390378"]"Iron Man 2,"[/movie] in which both men appear, but rarely interact. Downey is back as Tony Stark, the billionaire industrialist and lovable egomaniac who revealed himself to the world as Iron Man at the end of the first film. [article id="1638585"]Rourke lumbers into the tale as Ivan Vanko[/article], a muttering renegade physicist with a mouthful of metal and a slab-like body festooned with crude tattoos. The tattoos have only slightly more import for the story than the character's pet parrot, which has none; but Rourke, with his brooding charisma, brings an effortless heavy menace to each of his scenes.

It's unfortunate that he doesn't have much in the way of dialogue (and a lot of what he does get to say, through a glutinous Russian accent, is unintelligible); but then he doesn't have much in the way of room, either. The movie is overstuffed with characters. Some are returning from the previous film: [article id="1638603"]Pepper Potts[/article] (Gwyneth Paltrow), Stark's personal assistant and love interest; "Rhodey" Rhodes ([article id="1638620"]Don Cheadle, replacing the apparently overpriced Terrence Howard[/article]), Stark's pilot pal; Happy Hogan (director Jon Favreau), his driver; and espionage honcho [article id="1637382"]Nick Fury[/article] (Samuel L. Jackson), who was briefly seen at the end of the first picture recruiting for a nascent superhero undertaking called the Avenger Initiative. ("I'm not ready to join your little boy band," Stark tells him here.)

New to the fray are Justin Hammer (Sam Rockwell), a scheming armaments manufacturer, and [article id="1638291"]Natalie Rushman[/article] (Scarlett Johansson), Stark's new legal-affairs hotshot, who is not in any way what she seems. Also salted in are Garry Shandling, as a devious senator, and a number of familiar real-world faces, among them Bill O'Reilly, Christiane Amanpour and, inevitably, Marvel man Stan Lee. Not to mention a whole army -- and navy, and marine corps -- of heavily weaponized robot warriors. The movie is one long crowd scene.

The story, when it's allowed to emerge, is not without interest. Stark is slowly being poisoned by the electromagnet implanted in his chest to keep his heart going, and he's racing against time to devise a replacement. He's also acting out quite a bit, and the loyal Pepper has just about had it with his drunken party-boy antics. Meanwhile, Hammer is plotting to replicate Stark's Iron Man technology and use it for his own nefarious purposes -- and he's brought in Vanko to provide the necessary expertise.

The actors manage to keep all of this afloat, just about, but it isn't easy. Downey's familiar stream-of-consciousness jokes, jibes and multilayered asides have the happy tang of on-set improvisation; and Paltrow brings an almost connubial warmth to Pepper's tentative relationship with Stark -- which in turn clears the field for Johansson's smoldering sex-glow. (Handing the hero a martini, she purrs, "Is that dirty enough for you?") These characters are so much more fun than those in the usual run of comic-book pictures that you quickly begin to resent the standard-issue apocalyptic fireworks by which they're continually obscured. The best of these big-bang scenes comes near the beginning, when Rourke's Vanko -- who nurses a murderous grudge against Stark -- shows up at the Monaco Grand Prix, where Stark is driving in competition, barges onto the course in fearsome electro-whip armor of his own design and proceeds to wreak some fairly inventive havoc. After that, though, the endless smackdowns, super-chases and general incendiary pandemonium start to grind us down -- it feels like we're watching "Transformers 3" -- and we soon realize that fight scenes involving faceless actors in big titanium battle suits sound like nothing so much as a multi-kettle kitchen accident.

Downey rises above the hullabaloo with some sharp lines (under siege by his nemesis, he says, "I'm fending off a Hammeroid attack"); and Rockwell, the most valuable player in many a movie he's been in, has a very funny scene riffing on the virtues of the latest Hammer munitions. ("This can bust the bunker under the bunker you just busted.") There's also a tough, tightly edited scene in which Johansson's character, suddenly togged out in a black-widow catsuit, terminates an entire hallway full of killer goons. It's the most stylish action interlude in the whole movie, and the picture might have benefitted from a lot more of this sort of kinetic concentration -- and a lot less of just about everything else.

("Iron Man 2" is a Paramount Pictures release. Paramount and MTV are both subsidiaries of Viacom.)

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