Hey, fanboys. Yeah, you guys, the ones who flooded my inbox with e-mails after I trashed Zack Snyder’s “300,” wishing birth defects on my unborn children and suggesting that perhaps my husband isn’t — ahem — keeping me satisfied.

Yes, I’ve read “Watchmen.” I understand why it matters culturally, why it’s considered revolutionary in its exploration of flawed superheroes, why it moved you. It moved me, too. And still — or, rather, because of that — I found director Snyder’s adaptation hugely disappointing, faithful as it is to the graphic novel.

That rigid reverence should please purists — tiny details from individual comic-book panels are recreated lovingly on the big screen — but it also contributes to the film’s considerable bloat. At almost three hours, “Watchmen” tries to cram in nearly everything writer Alan Moore and illustrator Dave Gibbons originally depicted, but then the ending feels rushed. (And it’s slightly different. That’s all we’ll say.)

Much of what made the graphic novel so compelling with the cadence of the writing. (Moore wanted no part of the movie, though, so you won’t see his name among the credits.) There’s a rhythm that sucks you in, with time shifts and overlapping story lines, often within the same panel. There’s a richness to the characters, their philosophical debates and their origin stories.

And there’s something powerful about reading those words and internalizing them that doesn’t translate cinematically, such as when the tortured Rorschach says in voice-over the same thing he wrote in his journal: “Beneath me, this awful city, it screams like an abattoir full of retarded children.” The line feels like bad pulp fiction, and like many others, it clangs on the ear when spoken. (David Hayter and Alex Tse co-wrote the script.)

If you haven’t read the book, though, you’ll be lost, especially during the opening titles that breeze through the story of the Watchmen’s predecessors (to the tune of Bob Dylan’s “The Times They Are A-Changin’,” one of several obvious song choices). Those were the Minutemen, mortals who dressed up in capes, leather and latex to fight crime in New York in the 1940s.

Now it’s 1985 — or, at least, a twisted version of it where Richard Nixon remains president — and members of a new generation of superheroes, the Watchmen, are caught in a murder mystery years after they disbanded.

One of their own, the right-wing military mercenary the Comedian (Jeffrey Dean Morgan), has been thrown out the window of his high-rise apartment. It’s up to his former colleagues, including Rorschach (an eerie Jackie Earle Haley), the good-guy Nite Owl II (Patrick Wilson), the sexy Silk Spectre II (Malin Akerman), the brilliant Ozymandias (Matthew Goode) and the godlike Dr. Manhattan (Billy Crudup), to dust off their get-ups and find out what happened, even as the possibility looms of nuclear annihilation at the hands of the Soviets.

Snyder has been hailed as a visionary director — primarily by the studio releasing the movie — but “300” and “Watchmen” both prove he’s really a skilled mimic, albeit one with visual flair. His violent New York is tangibly gritty, but at the same time some of his larger set pieces, like the ones that take place on Mars, look distractingly cartoony.

As for the performances, Wilson brings smarts and pathos to his mensch of a character, while Akerman, as the woman he loves, is too one-note. Crudup’s subtleties go to waste as the nude and radiantly blue Dr. Manhattan, the only Watchman who really does have superpowers. He’s depicted here through motion-capture, his soft voice providing sharp contrast with his character’s muscular physique.

Pity, too, because Dr. Manhattan’s complicated journey is perhaps the breathtaking story that “Watchmen” the novel has to offer.