Originally the producers wanted Maurice Jarre to write the music for the film orchestrally, but Jarre insisted on scoring the film electronically because he felt that it was the right approach for the material and also sets the tone of the film.
Originally there was a love scene involving Alex and Jane that was supposed to have taken place in the middle of the film involving nudity, but it was deleted for pacing issues and also because of the MPAA's new PG-13 rating guidelines. The love scene was featured in the film theatrically and on its original video release, but for its "Image" dvd release a PG edited cut print or TV version of the film was used for the transfer.
Kate Capshaw starred as the love-interest in not one, but two 1984 movies that featured a scene where a man's still-beating heart was ripped from his chest: "Indiana Jones and the Temple of Doom" and "Dreamscape."
One of three movies to come out within a year of each dealing with dream manipulation and it's potential consequences. The other two were Brainstorm, released a year earlier, and A Nightmare On Elm Street, released 3 months later.
The trivia item below may give away important plot points.
Chuck Russell, who cowrote the screenplay, was also the screenwriter for the third Nightmare On Elm Street. Dreamscape and the Nightmare series share very similar plot elements, particularly the killer using the victim's dreams to kill them in reality.