The early pre-release screenings of the movie were disastrous. The percentage of the audience who liked the movie fell into the mid-30s, and executive producer Mario Kassar realized the main problem was that the plot made zero sense. His solution: have the Ra character's dialogue subtitled, and made into information that presented a clear storyline. When these changes were made, the subsequent test screenings produced an overwhelming majority of positive reviews, and this carried the movie into becoming one of the surprise hits of fall 1994.
Jaye Davidson's dislike of the attention that he received after The Crying Game (1992) made him reluctant to take the role of Ra in this film. He didn't want to just turn the offer down, so he made what he expected to be an unacceptable demand of $1 million. This was accepted, and he appeared.
Ra's glowing-eye effect was added in post-production, because test audiences didn't think that he was alien enough. This trait was continued in Stargate SG-1 (1997), as an identifier to people who are taken over by the Goa'uld.
James Spader admitted that he did the film for the money, as he found the script to be awful. He said, "Acting, for me, is a passion, but it's also a job, and I've always approached it as such. I have a certain manual-laborist view of acting. There's no shame in taking a film because you need some f****** money."
David Arnold was working as a clerk at a record store in England when he was recommended to compose the score for this film. On the DVD's commentary track, Dean Devlin and Roland Emmerich admit that they were a bit nervous after hiring him, since his scoring experience at the time was limited to a few short films and only one full-length movie. However, their doubts were gone as soon as they heard what Arnold had composed, and they continued their cooperation with him on Independence Day (1996) and Godzilla (1998). Emmerich and Devlin also state that the quality of Arnold's score for the movie is best exemplified by the countless times it was re-used in trailers, TV spots and programs.
Roland Emmerich: [rain] (at around 6 mins) Roland Emmerich says in the commentary he loves rain and includes it in all his pictures.