There are many truisms about physical appearance, personality, and the lack of correlation between the two. Most are designed to pump up self-confidence, suggesting that people who aren’t conventionally good-looking make up for it with great personalities. But that's not always true. People have physical defects. People have personality defects. They can have one or both. It’s rare that they have neither.

Happy Face seeks to explore this complex idea, and it often succeeds admirably. Director Alexandre Franchi drew upon his struggle with bone cancer, his mother’s disfiguring and ultimately fatal cancer, and the stories of his diverse, starkly unique-looking cast to tell the film’s spiderweb of stories, and the result is a film that wears its heart on its sleeve - sometimes to a fault.

Centring around members of a support group for people with extreme facial differences, Happy Face drops the audience in the deep end from the get-go. There’s a man with no nose; a woman with incurable warts; a heavily-injured policeman; and people with other congenital or accidental issues that leave them looking different enough to be ostracised by the world. In most other films, these actors would be cast as villains or monsters. In Happy Face, we immediately meet them as real people, Franchi’s camera treating them as any other camera would treat any other person.

Their stories make up a great deal of the movie, but they’re not its central plot. That belongs to Stanislas, a pretty regular-looking young man who infiltrates the group under cover of bandages, in order to - in his words - get used to the idea of what his cancer-stricken mother will look like after facial surgery. Stan’s deception doesn’t go down well with his new friends, but he quickly finds his way back into their good graces with an unorthodox therapy idea. Instead of dealing with their issues internally, he suggests, why not get confrontational, rubbing people’s prejudices in their faces, daring them to be more insulting?

Stan’s audacious plan is responsible for some of the film’s best scenes, and some of its worst. When he storms in like Perfect-Faced Jesus, his pep talks are cringe-inducing; his plan of “breaking [the support group members] so they get over their fear of being broken” feels naive; the fact that he’s doing all this so he can get back into the group just seems nakedly self-serving. That said, scenes where Stan’s cohort take point in reclaiming their lives range from truthfully observational to genuinely triumphant, laced through with honesty and gallows humour.

The bluntness of Stan’s methodology is reflected in the script, which while underlaid with painful truths is executed with sledgehammer bluntness. References to Don Quixote, and an extended metaphor wherein Stan ascribes Dungeons and Dragons character archetypes to his friends, are belaboured to eye-rolling extremes. Narrative exposition, too, is delivered with a hilarious level of clunkiness. Worse, the audience is treated as clueless about most concepts explored in the film. At least when the characters engage in novice-level cognitive behavioural thearpy, somebody makes a “cock and ball torture” joke about the acronym CBT. That always privately amused me in therapy.

Most of that material seems secondary, though, to the most personal element of Franchi’s film: coming to terms with a parent seriously physically affected by disease. Stan’s over-the-top championing of his new friends is essentially compensation for his avoidance of his mother post-surgery. Stan’s terror at what his mother could have become is appropriately painful to watch. For anyone who’s failed to be there for loved ones, or whose loved ones failed to be there for them, it’s an uncomfortably familiar story, full of guilt and anger and regret.

Stan’s self-loathing is reflected, too, in the other characters, as negative elements of their personalities and backstories start to manifest. All have something to feel guilty about, and their attempts to overcome those inner issues are powerful and frankly surprising to see, given cinema’s tendency to depict the disfigured in black-and-white terms. The shades of grey in these characters’ inner selves are far more difficult to grapple with than their exterior appearances.

Happy Face is at its best when engaging directly with its supporting characters, and at its worst when engaging with them through hamfisted speechifying. Compared to last year’s festival favourite Chained For Life, which dealt with similar issues more subtly, originally, and artfully, it doesn’t fare well. Its ending is particularly puzzling, presenting the internet - brand-new, in the film’s 1992 setting that barely comes up elsewhere - as a place where others engage with ideas instead of race or sex or appearance. Viewed through 2019’s online paradigm, it’s unclear whether that’s a commentary on how catastrophically the internet’s lofty aspirations have collapsed, or simply naive and over-optimistic.

Just like its ending, and like its characters, Happy Face is a flawed and sometimes contradictory piece. But there’s real heart at its core, and its nakedly empathetic yet unbeatific treatment of its unconventional cast is something rarely seen in cinema.