Michael Madsen once claimed this was one of the few movies he had done that he was proud of, but referred to the film's sequel as "lousy" and admitted he only did it for a paycheck.
During the production, MGM opted not to shoot the "nightmare train" sequence to keep costs down. H.R. Giger was not willing to accept that, however, so he spent one hundred thousand dollars of his own money to finance the sequence.
Frank Welker, who provided Sil's alien sound effects, said it was one of the most strenuous on his vocal chords with the various types of screaming and screeching sounds he was asked to create, but he had a lot of fun regardless.