Budgetary restrictions help make independent features just about the only American movies worth watching these days. Unable to afford the special effects that have supplanted writing and acting in most Hollywood productions, indie filmmakers necessarily concentrate their energies on screenplays and performances. At the very least, their small-scale efforts retain a human dimension that has nearly vanished from Tinseltown’s machine-tooled, demographics-driven blockbusters.

You Can Count On Me, writer-director Kenneth Lonergan’s flatly titled directorial debut, won the best-picture and best-screenplay awards at this year’s Sundance Film Festival. It’s an intimate, carefully crafted film, perhaps better suited to television than the big screen. But Lonergan’s evenhanded empathy with his multidimensional characters and the high level of performances he draws from his cast make the movie consistently absorbing if, ultimately, somewhat less than fully satisfying.

Lonergan, who wrote the lively mob comedy Analyze This, opens with a terse, sobering prologue that casts a shadow over the rest of his narrative: A married couple die in a highway accident. A policeman sorrowfully delivers the news to their two young children. At the funeral, the silent, grieving sister and brother clasp hands, cementing a bond that will both sustain and vex them for the remainder of their lives.

Following opening credits depicting Scottsville, the film’s fictional upstate New York setting, Lonergan leaps ahead two decades and introduces us to the grown-up siblings. Sammy (Laura Linney) is a single mother who still resides in her childhood home and works as a bank loan officer. A churchgoer devoted to raising her 8-year-old son, Rudy (Rory Culkin), she maintains a half-hearted relationship with her commitment-shy boyfriend, Bob (Jon Tenney).

Sammy’s orderly existence is shaken up by the unexpected return of her younger brother, Terry (Mark Ruffalo), an embittered drifter who has escaped what he regards as the stifling confines of his hometown. Sammy’s pleasure at the prospect of this reunion crumbles when she discovers that the purpose of Terry’s visit is to seek a handout to assist the pregnant girlfriend he’s left behind. Terry bickers with his exasperated sister while assuming the role of surrogate dad for Rudy, who was abandoned before birth by his ne’er-do-well father.

Lonergan’s screenplay discreetly skirts the bathetic pitfalls of domestic drama. As the film evolves, we discover that his characters are more complex than they initially appear. Sammy’s placid façade conceals a reckless streak. She impulsively embarks on a clandestine affair with Brian (Matthew Broderick), her uptight boss whose pretty, ill-tempered wife is pregnant with the couple’s first child. Even Sammy’s consultations with her open-minded priest (wittily played by the filmmaker) fail to resolve her conflicted relationships with her two lovers and black sheep kid brother.

At first glance, rootless Terry seems bent on self-destruction, but his rebelliousness turns out to be a shield to protect a core of disillusionment and vulnerability. Bonding with Rudy, he liberates the boy from his overprotective environment, introducing him to the pleasures of fishing and pool halls and, ultimately, forcing him to face the truth about his feckless biological father.

You Can Count On Me proves to be a star-making vehicle for Ruffalo, an intense, brooding actor in the outsider mold of James Dean, Marlon Brando, and Jack Nicholson. With his shambling walk and swarthy features, he seethes with inchoate emotions, driven by the early loss of his parents and his inability to find a place or person that corresponds with his amorphous needs. Although the fair-haired Linney is improbably cast as his sister—the pair bear no trace of physical resemblance—she brings to the role the same intriguing combination of decorousness and libidinousness that sparked her performance as Mary Ann Singleton in the television miniseries Tales of the City. Rory, the latest spawn to emerge from the Culkin moppet factory, turns out to be the best so far, an introspective child performer without a trace of cuteness. Only Broderick falls short of the ensemble’s excellence. His horny control freak Brian is cartoonishly callow, a stick figure in a film otherwise populated by rounded characters.

Atmospherically photographed by Stephen Kazmierski and discreetly underscored by Lesley Barber’s mixture of chamber and country music, You Can Count on Me undeniably fulfills its modest ambitions. All that’s left to debate is whether Lonergan should have taken a larger bite of life than he’s chosen to chew. At the fade-out, his characters, whom we have come to know and care about, remain essentially unchanged. “Life’s like that,” observed my companion at the press screening, whose admiration for the movie surpassed mine. She’s right, of course, but the question remains whether it’s unreasonable to desire more from a work of art than an accurate reflection of reality. CP