Every few years, a comic book movie that is based on real life appears, and most often they appear at Sundance, the January-set indie film festival that rival Comic-Con for celebs, parties and standing in the street looking for a place to drink free alcohol.

The American Splendor film triumphed at Sundance back in 2003; more recently Save the Date, based on the work of Jeffrey Brown, had a more modest debut.

But this year, The Diary of a Teenage girl, based on the hybrid novel/comic by Phoebe Gloeckner, and directed by Marielle Heller is getting very strong reviews. The film stars 22-year-old Bel Powley as Minnie Goetz, a teenage girl whose emerging sexuality finds an outlet in an affair with her mother’s boyfriend. (Kristen Wiig and Alexander Skarsgard play the mother and boyfriend.) Strong reviews have led the way to the film already being picked up by Sony Classic Pictures.

Todd McCarthy at The Hollywood Reporter loved it:

In this gutsy, intimate and assured debut, Marielle Heller accomplishes just about everything all young independent filmmakers say they want to do when starting out: to create a personal, fresh, distinctive work in their own “voice” that will then, of course, make their careers. Heller has pulled this off in a remarkably vibrant and frank look at one precocious teen’s emerging sexual life — a film with the stuff of life coursing through its veins and sex very much on its brain. The Diary of a Teenage Girl is the kind of film Sundance prays for every year: one that indelibly puts on the map a talented director the festival can then forever claim as one of its own. This will be one of the significant indie titles of the year and a good commercial bet — a film many young women will see more than once.

Anisha Jhaveri of Indiewire gave it an A-

Shocking but genuine, poignant and hilarious, “Diary of a Teenage Girl” could well become one of the more memorable entries in the Sundance Film Festival’s U.S. competition. Minnie’s story may be a singular one, but its essence will undoubtedly strike a chord — not just for women, but for anyone who recalls the befuddling emotions that plagued and enriched their teen years in equal doses.

Variety’s Dennis Harvey also liked it:

Translating tricky source material to the screen with flying colors, actress Marielle Heller’s feature directing debut, “The Diary of a Teenage Girl,” manages to plunge into the too-precocious sex life of a 15-year-old girl without turning exploitative or distasteful. This adaptation of Phoebe Gloeckner’s heavily autobiographical novel is ideally cast and skillfully handled, making for a salable item likely to stir some attention-getting controversy and win favorable reviews in territories where the subject matter (which is depicted not graphically, but with a fair amount of nudity) doesn’t create daunting censorship problems.

Gloeckner is a powerful storyteller and she has found a sympathetic collaborator in Heller, who previously adapted the material into a stage play; animations based on the comics part of the book are used throughout the film. The cartoonist, who currently works as a professor at the University of Michigan, was on the set for filming and went to Sundance for the premiere. Several interviews with Gloeckner about the experience are available: this audio interview and a profile here.

Bonus video: Wiig and Skarsgard talking about their characters.

The acclaim for the film will hopefully give some of Gloeckner’s other works some attention as well, although they aren’t that easy to find. A Child’s Life, which collects most of her comics, including ones which expand on the events of Diary, is OOP, although you can readily get a used copy. Hopefully that will change soon, and also maybe Gloeckner will do some more comics? A voice as honest and clear as hers is always needed in comics.