At a recent Q&A at BAM Cinematek, John Korty revealed why there was a version of the film with strong language. The film was always intended to be appropriate for young children, and Korty's final cut was almost identical to the 1991 home video release. After answer prints had been made based off his final cut, Korty went to New York to begin pre-production on another project while test screenings of "Twice Upon a Time" were taking place in California. Bill Couturié, one of the film's producers and co-writers, noted that college-aged audience members frequently walked out during the first ten minutes. After nearly the entire audience at a screening at USC walked out, Couturié reassembled most of the voice actors to record more profane versions of the film's dialogue in the hopes that it would keep teens and adults interested enough to watch the film to completion. John Korty was kept completely out of the loop on these changes and didn't find out until he was watching the film at its premier. Korty was furious, even more so when he found out release prints were made using this more profane version. Theater owners didn't know these changes had been made either, and one of the few theaters in the country to show the film ran it on a double bill with the G-rated The Secret of NIMH (1982). When outraged parents notified theater management, Twice was pulled from further showings.
The trivia item below may give away important plot points.
A storybook tie-in, apparently released before the film, shows some fairly major plot differences from the film's final cut. Greensleeves originally is captured much later in the story, and introduces Ralph and Mum to the FGM. Greensleeves then tries to get the spring back to the Cosmic Clock, but is captured by Rudy before he can do so. The ending was also slightly expanded; Ralph and Mum are told by Greensleeves that they must now become guardians of the Cosmic Clock.