Still flush from the success of his critically acclaimed documentary “Spellbound,” writer and director Jeffrey Blitz turns from the spelling bee to high school debate in the quirky and dark drama-comedy “Rocket Science.”

In true indie tradition, the narrative fiction film resists the usual clichés and plot developments that we’d expect from Hollywood’s high school romance/coming of age genre (think of it as the anti-Ferris Bueller). Unfortunately, in its ambitious attempt to be many things to many people, “Rocket Science” is weighed down by a cringe-inducing narrative voiceover that adds cheese to an otherwise refined performance by the cast, and a bloated resolution that leaves us feeling slightly unsatisfied.

Teen angst has a whole new dimension for protagonist Hal Hefner (newcomer Reece Daniel Thompson), a withdrawn, passive boy whose severe stuttering problem keeps him isolated from the rest of the world. Part of the problem is his family: Hal’s parents are divorced and he has a psychotic kleptomaniac for a brother (Vincent Piazza). As the lead, Thompson does a credible job as this troubled character, who must deal with an apathetic world that defies Hal’s every attempt to gain some control over his life. Hal’s faltering speech comes across as genuine, although some credit should go to Blitz, who was had a stuttering problem himself in childhood.

The rest of the characters are as admirably cast. His would-be love interest, Ginny Ryerson (Anna Kendrick, in a marvelous breakthrough performance), is the preppy perfectionist of the school debate team, whose ice-cold ambition drives her to do whatever is necessary to win. She convinces Hal to become her debate partner, and he jumps in headfirst, hoping to master love and public debate in the same sitting. Aaron Yoo nearly steals the movie as Hal’s curiously surreal friend Heston, who casts a strange otherworldliness that would put E.T. to shame. Despite his limited screen time, Yoo delivers some of the movie’s sharpest and funniest lines with his soft-spoken delivery.

To its credit, “Rocket Science” is eloquent in its portrayal of Hal’s life and his struggles with both the everyday problems of love and relationships and the not-so-ordinary problems that confront him in the cutthroat world of competitive debate.

The cinematography helps to ground the film in the compellingly nondescript image of New Jersey suburbia, and gives us the documentary-like realism that made “Spellbound” so powerful. This realism is constantly in tension with the whimsical soundtrack by American musician Eef Barzelay that is classical, folksy, and disturbing at the same time.

The problem comes as Blitz increasingly relies on this tension of real and unreal to take viewers through some absurd twists in the plotline, making events seem jerky and disjointed. The result is a movie that loses momentum in its second half as relationships slowly sink into irrelevance. The debate competition finale brakes too early and abruptly, and we’re left with twenty minutes of depressing anticlimax.

Despite its high-caliber casting and novel approach to the overused underdog premise, “Rocket Science” never really decides whether it wants to be dramatic, insightful or funny. Audiences aren’t looking for a cookie-cutter happy ending, but finding a satisfying climax really shouldn’t be rocket science.

—Staff writer Andrew E. Lai can be reached at lai@fas.harvard.edu.