Handed the keys to a potential blockbuster comic-book franchise, Sam Raimi did exactly what you wouldn’t expect in 2002’s original Spider-Man: He made it fundamentally about a nerdy kid who couldn’t pay the rent and never got the girl. Tasked with topping his own runaway success in 2004’s Spider-Man 2, Raimi again defied all industry logic: He created a paean to heroism and self-sacrifice. They were both dizzying adventures, but at their core was Raimi’s vision for popcorn cinema where naked emotionalism trumped Spandex and power-punches.

Had Spider-Man and Spider-Man 2 not raised the bar so high, it’s likely that Spider-Man 3 might have felt like something … more. It makes the sequel mistakes the second installment refused to make, and ends up straying from the soul that had made its predecessors soar. In the wake of two near-masterpieces in their genre, mere satisfying summer entertainment somehow seems like a huge disappointment.

Launching from an efficient the-story-so-far opening credits montage, the story picks up with Peter Parker (Tobey Maguire) in something of a happy place. He and Mary Jane Watson (Kirsten Dunst) are a couple at last, and his alter ego Spider-Man has won over the hearts of New Yorkers. But Peter’s bliss makes him oblivious to aspiring-actress Mary Jane’s career struggles, and he’s caught off guard when his former friend Harry Osborn (James Franco) uses the technology of his dad, the late Green Goblin, to pursue vengeance for his father’s death. And that’s saying nothing of the escaped convict Flint Marko (Thomas Haden Church), who stumbles into an experiment that turns him into the disintegrating/reintegrating Sandman, or the funky black slime that crawls out of a meteorite and hitches a ride on Peter’s moped.

That’s a whole lot of stuff going on—and that’s a whole lot of what doesn’t quite work in Spider-Man 3. Super-hero sequels have tended to fall into the ante-upping trap of piling on the extra villains and new characters with each subsequent installment, where Spider-Man 2 wisely kept the focus on its central pair. This time around, screenwriters Ivan Raimi and Alvin Sargent overload the plot with conflicts: Sandman’s personal tragedy-driven quest for cash; Harry’s lust for Peter’s blood; another woman, Gwen Stacy (Bryce Dallas Howard), to make Mary Jane jealous; Peter’s internal turmoil as the alien goo transforms his personality; a rival photographer (Topher Grace) with designs on Peter’s job. Don’t worry if you don’t like one challenge for our hero, because there’ll be another one coming along shortly.

Those challenges result in some battle sequences, and it’s here that the series continues to sparkle. Raimi choreographs Spidey’s fights with a remarkable flair—zipping between buildings and through spaces in girders, skimming the streets as though Manhattan traffic were some gnarly wave. And there’s still a pummeling physicality to the way he subjects Spider-Man to punishment that forces him to bend, even if you suspect he’d never break.

Last I checked, though, the question that drove the Spider-Man movies was not whether Peter’s body would break, but whether his spirit or heart would break. While Raimi finds time for a few effective scenes between Peter and Mary Jane, it feels like you have to wade through an awful lot of peripheral material to get to them. There’s nothing here to match the climactic apartment scene in Spider-Man 2 for poetic romance, nothing close to the end of the big elevated-train battle where New Yorkers come to Spidey’s aid. The problems of two people may not amount to a hill of beans, but they’re what made us fall in love with Peter and Mary Jane.

Raimi isn’t so far gone that he forgets any semblance of a lighter touch, including a clever bit involving Peter’s attempt at a marriage proposal in a fancy restaurant. Raimi still had some sense for what made the earlier films unique; he simply doesn’t commit to that uniqueness in the same way he had previously. Spider-Man 3 turns out to be a lively, energetic super-hero movie. And, unfortunately, that’s also all it turns out to be.

SPIDER-MAN 3 ( * * * )

Directed by Sam Raimi. • Starring Tobey Maguire, Kirsten Dunst and Thomas Haden Church. • PG-13, 140 min. • At the Century Cinemas Del Monte Center, Maya Cinemas, Northridge Cinemas.