Dennis Quaid was the first and only choice for Alex Gardner, after the producers loved his dedication for the role and the project during it's preproduction stage.
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.
Was the second film to be Rated PG-13 under then new MPAA ratings guidelines following Red Dawn, which had come out weeks prior to this film's release.
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.