I cannot believe World's Greatest Dad was made. If it has cost 50 grand and starred a bunch of nobodies, I could see it. But as a Robin Williams vehicle, and looking like it cost a couple of million or more, the film feels like an anomaly. The movie - a comedy about a father who takes immense advantage of his son's death - is beyond black. Comedies about teen suicide will always bring comparisons to Heathers, but this makes Heathers look like a Disney movie. And more than that, the film is brilliant.

World's Greatest Dad marks a whole new era for Bobcat Goldthwait as a filmmaker. His first two efforts, the interesting but flawed Shakes the Clown and Sleeping Dogs Lie, were transgressive in subject matter and filled with dark comedy, but they feel like dry runs for this film. World's Greatest Dad is beautifully shot, almost to the point of slickness. But that slickness helps sell the darkness of the comedy, and it makes the transgressions feel all the more extreme. In a gritty looking, handheld film a father using his son's death as a way of getting laid wouldn't shock quite as much as it does in a movie that looks like a Fox Searchlight mainstream indie.

Goldthwait's script is amazing, constantly upping the ante for the characters and for the comedy. There's a running gag with Bruce Hornsby that becomes absolutely sublime, but Goldthwait knows exactly when it has run its course, and he avoids making the mistake that so many other comedy directors make of milking the gag dry (see Tom Cruise in Tropic Thunder). Every joke feels like that, like he's taking it as far and as funny as he can without going too broad and ruining it. It's a remarkable display of comedic self-control.

Robin Williams is the center of the film, playing Lance, a basically decent high school poetry teacher who has no luck with his attempts to beome a published author and with a son who is a resolutely despicable douchebag. Spy Kid Daryl Sabara plays the son, who is given absolutely no positive side; he's a sick porn-obsessed pervert and misogynist, an inveterate hater of seemingly everything including music (all music) and film, a complete moron and a generally unpleasant, oily human being. When he accidentally kills himself by auto-erotic asphyxiation, Lance first meddles with the scene to make it seem like a suicide, saving his son a final post-mortem embarrassment. But when the suicide note he faked becomes a sensation around the school, he begins to use the situation to his own increasingly self-centered and cynical advantage. Lance spends the first half of the movie being completely put-upon by the principal, his son, and his girlfriend, a fellow teacher he sees in secret. He's the picture of a genial lump, so when he begins exploiting his son's 'legacy,' you're still on his side even as you cannot believe the film is going where it goes. It's one of those restrained Robin Williams performances that reminds you this guy can be so much more than Elmer Fudd and black people voices.

Goldthwait's script is heavy on transgression, but it's also filled with piranha sharp satire. He targets everything from stupid teenagers to therapists to talk show hosts. The satire becomes starker at this year's Sundance. One of the other films playing here is a documentary called Boy Interrupted, made by parents trying to cope with the suicide of their 15 year old son; now I wish I had seen that movie so I could compare and contrast. The only elements of the film that don't feel the sting of satire are the nerd elements; who knew that Bobcat Goldthwait was the kind of guy to write a Simon Pegg quote about zombies into his film, or have an Alamo Drafthouse Tyler Stout poster for The Thing hanging on his main character's wall? Lance is a big scifi geek - the novel he's writing at the beginning is called Door to Door Android, and features Willy Lowbot - and his interests make for great little 'Check that out!' moments and references in the film.

World's Greatest Dad is a movie that will soon become a litmus test. You'll judge people on whether or not they've seen it, and whether or not they like it. It's also a blast of refreshingly dank air - it's possible to make a movie as loaded with cynicism and darkness as this one and have it be not only great but also funny and, in the end, sort of weirdly sweet. It's also a huge triumph for Goldthwait; after World's Greatest Dad he's rocketed to the top of my filmmakers to watch list. But even if he never makes another film after this, World's Greatest Dad is an amazing work of dark, dark genius.

10 out of 10