World's Greatest Dad isn't actually his film debut, but it's the first movie of his that I've heard of, unless you count the 2003 Comedy Central movie Windy City Heat. Which I don't, because I remember it being really bad.
It stars Robin Williams as Lance Clayton, a high school English teacher and wannabe bestselling author -- as well as father to an intensely screwed up, but hilariously straight-shooting son (Daryl Sabara, who will evidently be appearing in Robert Rodriguez's Machete this year). Kyle Clayton hates just about everything: movies, music, father-son outings, you name it. His main hobbies include spanking it to scat porn and attempting auto-erotic asphyxiation.
The film begins with Lance finishing his fifth novel manuscript, which he proceeds to take to work and drop in the mailbox clearly labeled "NO OUTSIDE MAIL." The principal informs him that his poetry class could be dropped next semester if it remains unpopular. Like a schoolboy,
The dialogue here -- especially between father and son -- is razor sharp. The awkward, revealing moments feel vaguely similar to what you might see in a Judd Apatow picture, except not overdone. Goldthwait has proven that you don't have to direct your actors to ham it up to pull off ironic humor -- something Michael Cera ought to learn before playing the same damn character again.
And lest you think this is a pure comedy, which is what I expected, wait till you hit a major turn halfway in. As if he had to prove it again, Williams demonstrates once more that his acting chops are not limited to wacky outbursts and impressions of old nannies. Its originality, poignance, and devious sense of humor make World's Greatest Dad an excellent rental or Netflix Movie Viewer pick.