He also directed one movie, the 1950 film short Un Chant d'Amour.
Ubu.com has it online here. It contains full male nudity, just so you know.
Senses of Cinema says,
Apparently made for the private porn collections of wealthy French gays, and later disowned by an embarrassed Genet ... Un chant d'amour (1950) was banned from public exhibition in France upon its initial release, and has won only sporadic screenings since, often in censored form.
it holds its own today as one of the wisest and truest gay films: most others look stupid by comparison.
Slant Magazine says,
Genet's overpowering 1950 short is a milestone not just of gay rebellion but also of pure sensual expression in film, a polemical vision of desire forged with the provocateur's randy ardor and the artist's spiritual directness.
A revolutionary vision of emancipation through sensuality, Un Chant d'Amour is a song of love both universal and eternal.
DVDTalk describes it as "an effective film, albeit a tad clumsy and pretentious" and says it "a progressive and interesting experiment worth the time one is willing to put into it."