Grade: A-

If this summer’s trend continues, we’ll have to stop complaining about so many movies being sequels. Hard on the heels of the outstanding “Shrek 2” and “Harry Potter and the Prisoner of Azkaban” comes “Spider-Man 2,” a movie that’s sleeker, more exciting and better constructed than its already enjoyable predecessor. It’s also–and this is truly remarkable, given the subject–genuinely affecting from an emotional standpoint, with a central character so nicely written and a lead performance so finely tuned that they take the film well beyond the category of an upper-tier popcorn flick, which is what the original basically was.

The first “Spider-Man,” the origin issue as it were, took its lead from Richard Donner’s 1978 “Superman,” and in many ways this follow-up is reminiscent of Richard Lester’s “Superman 2” of 1980, which was also in some respects the superior film. Both are essentially “crisis of identity” movies, in which the hero comes to doubt whether devotion to his mission is really worth the personal sacrifices it requires, particularly in terms of romance; and in each case he temporarily abandons his alter-ego until a crisis–and his conscience, of course–recall him to his destiny. The renunciation-and-return scenario is an almost obligatory second act in this kind of myth, but in the present instance screenwriter Alan Sargent (with important assists from Alfred Gough, Miles Millar and Michael Chabon), director Sam Raimi and star Tobey Maguire work it out so expertly that it seems fresh and vital. In the first forty minutes, which manage to be both charming and touching, Peter Parker (Maguire) suffers minor humiliations–getting fired from his job delivering pizza because of his tardiness and being reprimanded by a professor (Dylan Baker) whose classes he’s missed–while suffering pangs of guilt over the death of his uncle Ben (Cliff Robertson, doing an afterlife cameo), watching his widowed Aunt May (Rosemary Harris) struggling to hold onto her house in the face of financial problems, and resisting the impulse to reveal his feelings for Mary Jane (Kirsten Dunst), the girl he’s always loved, who obviously reciprocates but can’t understand his standoffish attitude. His periodic forays into crimefighting as Spider-Man are clearly interrupting his attempts to live a normal, happy life, and things are made worse by the fact that Jonah Jamieson (J.K. Simmons), the volatile editor of the Daily Bugle who depends on him for photos of Spidey, continues to attack the masked man in print as a criminal, and Peter’s best friend Harry Osborn (James Franco) blames Spider-Man for the death of his father Norman (Willem Dafoe), also known as the Green Goblin from film one, and is furious with Parker for protecting the wall-crawler’s secret identity. Peter’s psychological demons even have a physical side: his powers occasionally fade out, sending him crashing painfully to the ground. When Mary Jane finally despairs of Peter’s ever coming around, she gets engaged to heroic astronaut John Jamieson (Daniel Gillies), Jonah’s handsome son–one of the things that ultimately persuades him to give up being Spider-Man. Unfortunately his resolution coincides with the appearance of a new super-villain, Doctor Octopus (Alfred Molina), a once-principled physicist much admired by Peter but possessed by some malicious metal tentacles that become lodged in his body during a catastrophic experiment to use fusion as a source of unlimited power. When Doc Ock threatens Aunt May and falls in with Harry’s desire to capture Spider-Man, a confrontation is inevitable–and Peter’s rejection of his destiny has to be reconsidered. (So too do Mary Jane’s marriage plans.)

What’s so satisfying about “Spider-Man 2” is that while the narrative is faithful to the spirit of the comic, it actually goes beyond the books in its portrayal of Peter’s plight, making it curiously touching but not maudlin; in effect it humanizes the material in the way that last year’s “Hulk” tried to do, but more effectively because its touch is lighter and its approach more nimble. Much of its success in this regard is due to Maguire, whose quiet good nature and soulfulness (just watch those doe-like eyes) invest the potentially cartoonish character surprising richness and depth: a scene in which he finally confesses his feelings of guilt over Uncle Ben’s death to his aunt is really quite powerful. Harris contributes to the emotional weight too, as also does Dunst, sweet and personable as the conflicted Mary Jane (the fact that she’s starring as Gwendoline in a revival of “The Importance of Being Earnest” is a witty commentary on the problems that stem from Peter’s double life). Only Franco, whose simmering rage as Harry doesn’t get much past the graphic novel level, doesn’t quite click. Even Molina’s villainous turn is remarkably subtle: he eschews the lip-smacking style that Dafoe exhibited in the first picture, opting instead for a quieter approach that nonetheless allows for menace, and the split personality that the writers have built into the character is a nifty mirror image of Parker’s own inner conflict. On the other hand, the picture doesn’t disappoint when it comes to the action moments: Spidey and Ock have a number of fine battles, including a spectacular face-off on a speeding L-train that temporarily makes New York look decidedly like Chicago. (The effects, it must be noted, are much smoother this time around, though they retain a bold comic-book patina. To rewrite the tag line from the original “Superman,” you may believe that a man can swing.) But the confrontations are more carefully judged, too, limiting the bone-crushing nature of the violence that disfigured the final act of the last picture. They also leave room for the human element: the conclusion of that L-train sequence, for example, includes a “we’re all in this together” moment that works in spite of its obviousness. And the picture doesn’t forget the need for humor (something “Hulk” conspicuously lacked) either: a sequence backed by “Raindrops Keep Falling on My Head” is winning, some of Spidey’s quips are pretty good, and Simmons’ bombastic editor is used to fine farcical effect.

It may be, however, that the very skill of Raimi–whose assurance in deepening this material shows a real maturation in his customarily exuberant, colorful but somewhat sophomoric style–will limit the popularity of “Spider-Man 2.” The bonanza status of super-hero pictures depends on multiple viewings by adolescent kids, who may find the emphasis on the human side at the expense of non-stop, slam-bang commotion a turn-off (much the way that boys’ eyes glazed over whenever the romantic subplot popped up in B-westerns of the 1950s). Even if that happens, though, it won’t alter the fact that this is one of the best pictures of its kind ever made, not only beautifully crafted (with fine cinematography by Bill Pope, expert production design by Bob Murawski and a grandly supportive score by Danny Elfman) but intelligently imagined and realized. The smartness of the movie is perhaps best encapsulated in a scene in which Parker, trying to convince himself that he’s recovered the Spidey powers that have been failing him, attempts a leap between two skyscrapers, misses, and crashes onto a car; he gingerly lifts himself and struggles to walk away, complaining about his back. The sequence is obviously a reference to the fact that Maguire was nearly replaced in the title role of “Spider-Man 2” because of back problems (or, if you believe other accounts, his demand for a big raise), and it’s at once cheeky, exhilarating, funny and genuinely moving. That’s the rare combination that suffuses the whole film and makes it such a triumph of the super-hero genre.