The WorldCon voters were really into comedies in the mid-70s apparently. Sleeper is a Woody Allen film (writer, director and star, as is often the case with his films), and it is from the earlier slapstick era of his career. He clearly wants to be Buster Keaton or Charlie Chaplin, and there are long sequences of physical comedy.
Allen plays health-food store owner and jazz afficianado (there’s a wonderfully inappropriate ragtime soundtrack throughout the film) Miles Monroe. Miles goes to the hospital in the 1970s for treatment of an ulcer and wakes up two-hundred years later in a dystopian future. Society is ruled by a totalitarian “Supreme Leader,” everyone has robot butlers, and people who disagree with the are brainwashed. Oh, and people just spend a few seconds in the “orgasmatron” rather than having sex.
Allen is revived by revolutionaries and then forced into hiding. He eventually disguises himself as Diane Keaton’s butler, and when she discovers him, he exhorts her to join him in rebellion.
The film is funny, though some of the slapstick material gets a bit tired (Allen is not Chaplin or Keaton). As science fiction, there’s nothing too original here (there is a parody of HAL9000), but it’s certainly amusing.