Summer arrives a few weeks early with the latest flashy, CGI-dominated comic book adaptation. This superhero, however, is not a youthful, heroic do-gooder, but a child prodigy-turned-playboy-mogul-technical-genius, Tony Stark, now president of a company specializing in state-of-the art weapons. Iron Man’s first forty or so minutes revel in Stark’s Bill-Gates-meets-James-Bond-lifestyle, so his change of heart, after he realizes that his weapons can actually kill (!) American troops, is laughable. The ensuing metamorphosis into his robotic, metal-clad alter ego steers the movie onto the right track (although a bit more with his humanoid robot assistants would have been welcome). As Stark, Downey is suitably (and annoyingly) glib at first, but loosens up a bit as the film progresses; Jeff Bridges is a fatherly corporate mentor/villain and Gwyneth Paltrow is more animated than usual as the girl Friday Stark obviously can’t live without (both personally and professionally). Audiences will cheer the Transformer-like Iron Man as he battles the no-discernible-nationality-but-definitely-Middle Eastern terrorists while rescuing assorted civilians, although much of the dialogue and plot whiz by before you can appreciate them — no doubt director Jon Favreau feared the audience tuning out during any non-action sequences. The film’s final battle is impressive if a bit too frenetically directed, but as these things go (at least for one unfamiliar with the comic books), it’s a lively, fun, occasionally thoughtful popcorn movie.