Iron Man 2 is the Vince Vaughn character from Swingers. He thinks he’s all growns up and he’s all growns up, but really, he’s just a silly, immature teenager. Coming from director Jon Favreau, who also plays Stark bodyguard Happy Hogan, and writer Justin Theroux, the sequel suffers from a litany of subplots and underdeveloped characters. It’s a fun movie. But it lacks the punch and fluidity of the first.

The film begins with an introduction to Ivan Vanko (Mickey Rourke, sporting his hair, gold teeth, and body makeup from The Wrestler) who apparently is the world’s ugliest and most psychotic physicist, comforting his dying father Anton. He then spends the opening credits creating some new technology from stolen Stark blueprints. Hmmm….

We cut to Tony Stark (the ever-fabulous but a bit tired looking Robert Downey Jr) who is losing the fight against palladium, which powers his tiny arc reactor embedded in his chest but is also poisoning him. Stark is also battling the politicians who want his Iron Man technology to fuel US military might. As the embattled Stark slowly hands his empire over to Pepper Potts (Gwyneth Paltrow) under the supervision of Stark Industries hottie Natalie Rushman (Scarlett Johansson), he discovers that Vanko has developed a new weapon based on the arc reactor technology.

In a deadly encounter in Monaco, Vanko is captured, but is immediately intercepted by Stark competitor Justin Hammer (the scene chewing, wonderful Sam Rockwell), whose military contracts have all been put on hold. Thinking Vanko is his ace in the hole Hammer hires him to complete a series of Iron Man drones for the military, apparently without supervision, allowing Vanko to manufacture a more advanced version of his own technological revenge against Tony Stark for some vague dishonor served to Anton Vanko by Tony’s father Hank.

Meanwhile, Lt. James Rhodes (Don Cheadle), seeing Stark’s self-destructive behavior, beats up Tony and steals the War Machine suit, bringing it back to the military for weaponizing. Enter Nick Fury (Samuel L. Jackson), who reveals Rushman as Agent Romanoff, tells Tony his father really loved him, and convinces Tony to keep looking for a cure to his palladium problem.

Blah blah blah. We’re only halfway through the movie and it feels like a thousand different threads, unskillfully woven together. Theroux clearly is outmatched by the demands of the studio, who must have told him, “Make it bigger, make it more.” Yes, it’s more, and yes it’s bigger, but somehow it misses the salient connection, the sense of togetherness and neat compactness that the first one enjoyed.

The action scenes are riveting, if moderately unbelievable (Vanko’s whiplash thingy is cute, but it wouldn’t be much of a match for a sniper bullet, ya dig?). The talky exposition scenes are long and often reveal less about the characters and more about the awful danger screenwriters face when the need to reveal information trumps the need to, I dunno, tell a good story.

Favreau’s direction here is actually effortless on screen, and is one of the reasons the movie is as fun as it is, considering all the script’s flaws. There is a steady hand at the helm, and Favreau knows how to punch up an action scene without losing all semblance of order through a blur of quick cuts. We actually see fight scenes and the flying suits and innumerable projectiles flying through the Las Vegas (edit: I remember a Stratosphere-esque building and what with all the plotlines, kinda forgot the Stark Expo occurred in Flushing, NY) air (how did millions not die in the finale?) are satisfying to see.

Downey Jr. is appropriately Stark-ish, but isn’t given much more depth than he had in Iron Man to make his character more interesting to watch. Also, Theroux gives him the palladium poison as a kind of mirror to Stark’s narcissism and ego, but hamfistedly introduces S.H.I.E.L.D as holding the answer to the energy problem. Where were you, Nick Fury, six months ago? The deus ex machina suitcase containing the answer to Stark’s physiological and psychological daddy issues is just weak.

While there is so much to be enjoyed in the film, and it’s not unsatisfying to watch, knowing how good it might have been in the hands of someone more disciplined at the keyboard brings the experience down a notch.