Noah Baumbach’s “Frances Ha” is, like Lena Dunham’s hit HBO series “Girls,” fixated on the insular, entitled world of artsy, twenty-something Manhattanites, where twenty-seven year-old bachelors are still bankrolled, unapologetically, by their parents, and barely employed comedy writers and sculptors refuse to relocate to cheaper, less happening outer-borough apartments.

Like Dunham, Baumbach bravely expects a sophisticated audience—many of whom long ago gave up on their artistic pursuits to secure a steady paycheck—to not only tolerate but fall in love with this lot of irresponsible malcontents. That he succeeds—half the time, anyway—is a commendable achievement, but one leaves “Frances Ha” slightly sour, wishing its creator had been a little less enamored with these characters.

The prominent females in “Frances Ha” are less similar to the sex-obsessed quartet in “Girls” than they are to the more chaste debutantes in Whit Stillman’s 1990 urban fairy tale “Metropolitan.” They may fawn over shallow, self-involved boys not worthy of their attention, and they may fret about their own appearance. But they do so with the affected, somewhat haughty air of the Victorian novel heroines they likely idolized at their prestigious college (in this case, Vassar).

“Don’t you just love him? Wouldn’t you love to date him?” says the awkwardly sunny, aspiring modern dancer Frances (the always lovely Greta Gerwig) to her dowdier ex-roommate Sophie (Mickey Sumner) about her new roommate Lev (Adam Driver).

“Undateable,” says Lev and Frances’ other roommate Benji (Michael Zegen), every time Frances does or says something uncool. These people are quaint with a capital “Q.” Despite their reliance on cellphones and Facebook, their problems are rendered more old-fashioned by Sam Levy’s luminous black and white photography, which Baumbach selected, he said after a recent screening, to give the film “an instant nostalgia” (when the characters trade graphic oral sex stories or use the “F” word, it has a deliberately jarring effect.)

The central drama in “Frances Ha” is the gradual drifting apart of Frances, who bounces capriciously from apartment to apartment, and Sophie, a more stable publisher, who, despite her misgivings, decides to marry and move to Tokyo with her long-time beau. One day the girls are cuddling in bed, giggling about their co-dependency (“lesbians without the sex,” one of them says), making fun of corny boys that like them; the next, Frances is on her own, left without even pots and pans in her now-bare apartment. She’s forced into nomadic living, all the while watching Sophie blossom into adulthood.

At times, Baumbach proves just as strong at evoking Frances’ loneliness as he did when dealing with similarly indecisive characters in his 1995 debut, the more incisive “Kicking and Screaming.” Frances’ ill-advised last minute two-day trip to Paris—perhaps the least romantic cinematic Paris sequence ever—is a piece of comic brilliance. Frances oversleeps, meets no one of any significance after a long day out, and calls friends that don’t call her back—until she’s back in the States.

The script, by Baumbach and Gerwig, is often raw and heart-wrenching, as when one of Lev’s younger conquests tells Frances, “You look older than Sophie but not as grown up.” This is a brutal indictment, and somewhat accurate. When Frances lands a pathetic summer waitressing job at her alma mater, she towers, hilariously, over her petite coed colleagues. With her gangly frame, doe eyes and stuttering delivery, Gerwig has been perfectly cast. She’s the epitome of sexy gaucheness, and she’s paired nicely with Sumner, a willowy British actress who has a field day with Sophie’s Debbie Downer inflection and pointedly oversized glasses.

“Frances Ha” is certainly Baumbach’s most playful film. He’s wittiest when throwing in jazzy, jaunty music to amplify perfectly mundane situations (such as Frances getting a paltry tax rebate in the mail, or Frances “saving the day” by making late-night omelets for a hungry pack of returning bar-goers).

But the film often flags; scenes tend to peter out without a needed kick, or end with jokes that aren’t as quick-witted and delightful as Baumbach and Gerwig intend. For every scene that’s a surefire winner (Frances screaming at Sophie about the missing pots and pans), there’s a line trying to be insightful but actually making little sense.

“Don’t treat me like a three-hour brunch friend!” Frances yells at Sophie. What exactly is a “three-hour brunch friend”? Baumbach and Gerwig don’t really care if you’re lost. You’re either on board with these persnickety youths or you’re not. “Frances Ha” is a good-natured, frothy occasion, but its self-congratulatory snappiness can leave you feeling as alienated as its protagonist.