While there’s been a fair bit of speculation surrounding "Iron Man" - surrounding Robert Downey Jr. finally getting a high-profile leading role, surrounding the announcement that this lesser-known comic book series would be helmed by the lesser-known director Jon Favreau - the good news is that all of these unconventional choices meld together in an adventure that is captivating both in its realism and its restraint.

In fact, there’s something disarming about the title itself. This isn’t chiefly a movie about a man who can shoot spider webs, or about kids crawling through a wardrobe into a magical fantasy kingdom. It’s not focused on wild acrobatics or soaring special effects. Sure, we get plenty of that here, but there’s also something old-fashioned and concrete about the notion of a man melding iron into an invincible suit that can fly.

He doesn’t just float above the city; he crashes through it, and in this way, it’s a movie not for boys who love to see things blow up, but for boys who love the idea of being able to build something that can do amazing things.

It’s less a movie for the video game nerds than the science nerds.

But perhaps that was to be expected. Anyone who knows anything about the "Iron Man" universe is familiar with Tony Stark (Downey Jr.) who is not a guy who dreams of being a superhero, but a scientist who enjoys making two things: machines and money. Following in his father’s footsteps - a father who helped to develop the atomic bomb - Stark is a man who builds guns and missiles for the military, and who enjoys the lifestyle of the rich and famous.

A poster boy for the nation’s magazines, Stark crisscrosses the world in his private jet, when not cruising the streets of Malibu in his fancy cars, or bringing gorgeous blondes back to his hilltop mansion. But during a trip to Afghanistan to visit his buyers in the military, Stark is ambushed and abducted by forces who appear to be the Taliban.

In captivity, he’s forced to devise a device to implant in his body, to keep the shrapnel that has cut beneath his skin from damaging his vital organs - shrapnel caused by weapons that he himself designed, that the Taliban then stole from American troops. When he also builds a huge metallic suit that helps him escape and kill his captors, he returns to America a hero.

But once back home, he is no longer the least bit interested in weaponry - nor money for that matter. He instead tells his assistant Pepper Potts (Gwyneth Paltrow) and his business partner Obadiah (Jeff Bridges) that he is devoting his life to perfecting this concept of a high-tech armored suit, a suit he quickly uses to save the Afghan refugees who are now being killed by the Taliban, using American weapons.

Once Stark perfects a whole new suit, and Obadiah, turning his back on his former friend and partner, steals the technology to build a suit of his own in hopes of making a quick buck, it’s a lot of fun watching these metal monstrosities clash in true "Transformers" fashion. Whether throwing punches of flying through the sky with F-16s in hot pursuit, these robots are truly majestic creations.

But what ultimately sets "Iron Man" apart, and what will no doubt assure that it returns with a sequel in 2010, is that as much fun as these high-tech standoffs are, it’s even more fun watching Downey Jr. toil away alone in his lab. This is more a movie about testing oneself in the lab than about saving the city, more about a man pushing his own scientific knowledge to the brink than about watching things go boom.