HBO's "Entourage" has been criticized for how it portrays women. As the show makes its way to the big screen, The Post's Alyssa Rosenberg says there's actually hidden feminism in the franchise. (Jayne Orenstein, Alice Li and Alyssa Rosenberg/The Washington Post)

Entourage” is the kind of movie that succeeds merely by meeting — and fitfully exceeding — expectations. But, seriously, did anyone expect all that much?

Perhaps it was a foregone conclusion that, in the age of synergies and verticals and brand extensions and dedicated audiences, a popular premium-cable series would absolutely, positively have to morph into a feature-length theatrical film. But even obvious cash grabs don’t have to be lazy and cynical. Some critics (this one) bemoaned the state of cinema and civilization itself when Disney announced the production of a movie based on one of its theme-park rides. Then the first “Pirates of the Caribbean” came out, and we were happily — delightedly — proven wrong.

The same can’t be said for “Entourage,” which, for the most part, plays like a padded-out episode of the HBO show about the young actor Vincent Chase (Adrian Grenier), who arrived in Hollywood in 2004 to find his fortune, with a squad of his Queens homeboys in tow. The posse included best friend and manager Eric (Kevin Connolly), Turtle (Jerry Ferrara) and Vince’s half-brother Johnny (Kevin Dillon), nicknamed “Drama” in honor of his self-seriousness as a Z-list actor.

The ensemble, continually on the hunt for the next beer, bong hit and babe to seduce, was reportedly based on the real-life friends of Mark Wahlberg, who executive-produced the series (and shows up for a funny cameo in the movie). Their antics possessed the frisson of firsthand knowledge, as well as confoundingly contradictory messages and impulses: “Entourage” presented a repulsive tableau of swaggering, dim-witted entitlement precisely at the same time it engaged in materialistic wish fulfillment at its most Dionysian. The viscous substance that held all the preening and posturing together was Vince’s agent, Ari Gold, a tightly clenched fistful of rage, ego and barely concealed insecurity.

Portrayed by Jeremy Piven in a one-man personification of the fear that Hollywood runs on, Ari is a moderately compelling antihero, far more interesting than Vince and the callow fellows he hangs with. And, as he did in the show, Ari single-handedly saves the movie version of “Entourage” from “Medellin”-scale disaster.

As the film opens, Vince is on a yacht in Ibiza, recovering from an impulsive marriage and taking a break from directing his first movie, called “Hyde.” A few scenes later, writer-director Doug Ellin — who created the original show — provides a helpful primer in the characters’ story arcs, enlisting Piers Morgan to interview Vince about his career, and jamming in all sorts of expository information about the guys in the process.

Eric is now due to be a father and Turtle has lost a lot of weight, but other than that, very little has changed in the “Entourage” universe, whose gravitational pull is a gaseous mix of booze, weed, overcompensating cars and the pervading funk of sexual anxiety and conquest. When women aren’t being idolized as ingenues, models and baby mamas, they’re being degraded as wifely scolds and objects of leering lust — on the part of Ellin’s T&A-obsessed camera — and outright contempt, by way of Drama’s startlingly nasty asides. One exception to the rule, barely, is Turtle’s love interest, who is played in a steely, askance-looking turn by the mixed martial arts fighter Ronda Rousey.

Just when you think you couldn’t care any less about any of it, Ari — who’s now the head of a studio — zips in to give “Entourage” the jolt it needs, if not for redemption then at least for forward propulsion. Ellin tries to keep viewers’ interest aloft by stuffing the movie with cameos by everyone from Armie (Hammer) to Warren (Buffett), but it’s Ari who earns the only legit interest or laughs, whether he’s nervously visiting a financier in Texas (nicely underplayed by Billy Bob Thornton), managing the millionaire’s meddling son (Haley Joel Osment), deciding whether to host the upcoming wedding of his longtime assistant Lloyd (Rex Lee) or, in one inexplicably hilarious scene, punching a picture of a cat in the office of the therapist he’s seeing with his wife (Perrey Reeves).

Piven is so in the pocket as the smarmy, aggressive, inappropriate Ari that, when the movie he’s in does little more than double down on the bro-ing out, the whiffed opportunities become all the more obvious. With the industry in economic and technological flux, caught between the exigencies of tentpoles and the aspirations to art, its bubble of impunity finally being punctured by investigations into gender representation and women’s pay disparities, the time is ripe for a truly penetrating satire of Hollywood folkways — a 21st century “Player.”

Ari and “Entourage” could have been just the kind of scabrous, self-referential critique of the entertainment industrial complex that would have allowed it to transcend its dubious provenance. Like Vince and his pallies, the “Entourage” movie is content to stay on the bright and shiny surface of a world that’s far more interesting at its hidden, Ari-like core.

½ star

(104 minutes, at area theaters) is rated R for pervasive language, strong sexual content, nudity and some drug use.