Sophie Brooks’ debut film, “The Boy Downstairs,” is a smart first feature for the NYU Tisch alumna. Although it might have gotten lost in the throngs of indie films, its merits position Brooks as a voice to look out for in the romantic comedy genre.

“The Boy Downstairs,” which Brooks both wrote and directed, premiered at the 2017 Tribeca Film Festival to mixed reviews. The film follows twenty-something-year-old Diana (Zosia Mamet) as she returns to New York to focus on herself and her writing after two years abroad. Mamet, famous for her role as Shoshanna Shapiro on the HBO series “Girls” makes her starring debut here. Diana lucks out in quickly finding a shiny, new Brooklyn apartment — the kind that makes the audience question how a struggling writer and retail-worker can afford — before learning that her new circumstances are bittersweet: her ex, Ben (Matthew Shear), lives downstairs, and his girlfriend (Sarah Ramos) is her realtor.

Mamet shined as her hilariously idiosyncratic “Girls” character Shoshanna, yet as the centerpiece of this romantic comedy, Mamet falls flat. It seems to be no fault of Mamet’s skill as an actress. During the film’s more emotional moments, Mamet is entirely believable, but her character is regrettably uninteresting, lacking a certain believability as the dry-humored protagonist of the film. Shear is similarly disappointing as the leading man and is arguably underdeveloped. There is nothing truly compelling about his character that makes us want him for Diana.

Yet the film’s script is impressive. The back-and-forth between Diana and Ben, Diana and her best friend, Gabby (Diana Irvine) and Diana and her landlady, Amy (Deirdre O’Connell) is laugh-out-loud funny at times. It’s the execution of these scenes that unfortunately fail to drive the film’s humorous quality home. Mamet and Shear have an unfortunate lack of chemistry, making it hard to believe them as a couple and to root for their relationship. Or perhaps, this lack of chemistry is uncannily believable: watching “The Boy Downstairs” feels like eavesdropping on a real relationship — ultimately boring if you aren’t uniquely invested in the parties’ lives.

Ultimately, “The Boy Downstairs” is less comedy than drama. It’s less about the relationship between Diana and Ben than Diana herself –– an incredibly complex character who doesn’t really know what she wants. What she does want she’s afraid to get because she’s deeply afraid of rejection, a truth which she relays to Ben during an intimate flashback to their relationship. She broke up with him because she was afraid their relationship wouldn’t work out, which leaves her vulnerable and exposed. It’s a narrative that’s tried and true. Brooks arguably may not have done anything novel with this trope, but she does explore it interestingly in her film.

“The Boy Downstairs” opened in theaters last Friday, Feb. 16.

Email Natalie Whalen at [email protected].