Transformers, Robocop, and this film all have robotic, metal-suited lead characters. But Iron Man is different. Thanks to a literate script and superb acting from Robert Downey, Jr., the tin can at the heart of this film has soul. And because he does, we care what happens to him.

Tony Stark (Downey), an inventor and the controlling force of a company that makes and sells weapons to the military, is acerbic, likable, and quick-witted, but lacks moral focus. As he returns from having given a glitzy sales pitch to military leaders, his convoy is ambushed and everything is blown up -- except him. He’s taken prisoner and wakes up to find that a fellow inmate, a genuine mad scientist, has installed a giant electromagnet in the middle of Stark’s chest to keep shrapnel from going into his heart. It’s powered by a car battery that Stark has to haul around. While imprisoned, the ingenious Stark constructs a suit of armor out of spare parts, and escapes.

Returning to the US after seeing the downside of what his weapons can create, Stark vows to turn his company’s efforts to peaceful means. His partner, Obadiah Stane (a shaven-headed Jeff Bridges), disagrees, and ultimately becomes the movie’s villain. Pepper Potts (Gwyneth Paltrow), Stark’s loyal sidekick, assistant, and potential love interest, if they could ever find time, is devoted to his welfare and does anything he asks. He trusts her implicitly. So when he disappears into his super-high-tech lab and starts working on a more refined version of the iron-man suit that aided in his desert escape, he withholds nothing from her.

As Downey plays him, Stark has a lot of fun making his armor. There’s much humor in these scenes, as we’re shown Stark’s failures and his adjustments. When he finally dons the full suit, you know it is really him inside calling the shots and controlling the robotics, which is what makes this superhero movie different. No matter what Iron Man accomplishes -- such as a quick kick-ass mission to Afghanistan to save a village from being terrorized by the thugs who’d captured him -- you’re always aware of Stark the man.

The movie has a few faults, the main one being that it is a little uneven. So much time is given to backstory and the creation of Iron Man that many of the current-day exploits seem crammed into too small a space. Because of this, a bit of the continuity goes overboard -- Stane seems to invent his own iron suit in just minutes, a task that has taken the talented Stark far longer. I’m not usually a fan of films over two hours long, but this one seemed to need a longer third act. Director Jon Favreau keeps things moving at a good pace most of the time, and knows how to get the best out of his talented cast.

The special effects are dazzling. As Stark zips around in the air, learning to fly, it’s a lot more astounding and believable than anything in any Superman movie -- and Stark doesn’t even have a cape. The lab robots and computer screens are ingenious and eye-opening -- Stark has some sort of holographic computer program that he can reach into and alter, going from the real to the virtual worlds without a hitch. The Iron Man costume itself is most appealing and impressive. It has a friendly look with a "don’t mess with me" overlay.

Iron Man is an exciting and entertaining popcorn movie that gets the summer season off to just the right start. There are many sequel possibilities, and I hope every one of them makes it to the screen -- as long as they star Downey and Paltrow. It’s exciting, for a change, to see such super actors in a superhero movie.

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