Azazel Jacobs’s “Momma’s Man” is a family film, but one of the least sentimental variations in history. Despite making its premiere at the Sundance Film Festival in January, it is a decidedly non-Sundance narrative that must have stunned Park City audiences, who might have assumed they were walking into the next “Little Miss Sunshine” when they read the title.

“Momma’s Man” is a sparse, insulated story about an immature man — the popular archetype of so many recent bloated Hollywood comedies — who is openly mocked by Mr. Jacobs for being the warped weakling that he is. But apart from mocking its main character, the film, which opens Friday at the Angelika Film Center, dissects the conventional view of “home,” suggesting it is not a place of emotional security and wish fulfillment, but a disorienting bubble that prevents us from realizing our full potential. Some have already referred to “Momma’s Man” as a comedy, but a few chuckles aside, this is a dim character study that will enthrall some audiences for far more serious reasons.

Mikey (Matt Boren) has just returned to New York City, leaving his wife and young child on the West Coast for a quick visit back East. The days tick by as Mikey settles into his old routine. But as he starts missing flights back home, it becomes apparent that he has no intention of leaving his childhood bedroom. A worried glance shared by his parents says it all. The fact that they are played by Mr. Jacobs’s real parents, Ken (a local filmmaking icon in his own right) and Flo, and that the film was shot in the Jacobses’ actual apartment, speaks volumes as to Azazel Jacobs’s own notions of home.

Mikey’s decision to linger around the house is a mystery, hinting at some deeper scar that has led him to want to return to the womb and assume a fetal position. But as days become weeks, his actions — or inactions — hint less at an argument with his wife or troubles on the job and more at something akin to a psychological breakdown. We witness Mikey’s regression. He scours his room for old comic books, starts strumming silly songs on his old guitar, and gazes up at the glow-in-the-dark stars pasted to the bedroom ceiling. He reaches out to old schoolyard friends and stages reunions with former flames who barely remember him.

In most other movies, revisiting the innocent glories of youth would be a gleeful trip down memory lane. Old romances would be resurrected, parents would becomes best friends, and Mikey would achieve something close to self-actualization. But Mr. Jacobs has no place for such trite celebrations. With each backward step Mikey takes — some funnier than others, as we realize even his best friends thought Mikey was pretty pathetic — Mr. Jacobs pushes back against such recent, lighthearted twists on emerging adulthood as “Failure to Launch” and “Step Brothers.”

But the blame doesn’t lie solely with Mikey. “Momma’s Man” intimates that Mikey’s parents are culpable in his devolution, enabling him as they try to give him space. With Mikey back in the house, the whole family becomes trapped in the past.

The laughs come to a halt when Mikey teeters at the top of a staircase, having retreated further within himself and reached a point of no return, unable even to get up the courage to leave the loft. Standing motionless outside the front door, looking down the staircase in a heavy sweat, he can’t get his feet to move. Mr. Boren’s astonishing performance has come all the way around, from a cute, chubby blob of good cheer to a tense, frightened ascetic.

If the movie is initially confusing, and then disturbing, what ultimately lends it poignancy is the art-versus-reality tug-of-war playing out right on the surface. As Mr. Jacobs’s camera makes its way through the cluttered chaos of the apartment he inhabited as a child, it seems the director himself wants not only to wrap his arms around a life that no longer exists, but to grasp a fading filmmaking community — one pioneered in part by Ken Jacobs — that wants to push aside the machinations of 21st-century Hollywood in a bid to resurrect the independent spirit of New York City circa 1965.

But for Mikey, the Jacobses, and the whole independent film movement there is no going back. In rifling through the themes of his own past, Mr. Jacobs has made a film that might just convince others to move beyond theirs.

ssnyder@nysun.com