John Baxter and Brian Hannant's original script was called 'Time Wars'. Originally the city in a bubble was to be pursued by just one evil robot. However, producer John Daly of Hemdale Films insisted that there had to be hordes of robots to be featured in several battles. According to Hannant, these late revisions to the script combined with the lack of extra budget led to the failure of the picture.
Second and final film directed by Brian Hannant and his third and final feature film as a screenwriter. Hannant's first film as director was Flashpoint (1972) in 1972. He was the screenwriter of Flashpoint (1972) and the co-screenwriter of Mad Max 2: The Road Warrior (1981) in 1981.
Petra is played by Carrie Fisher. Fisher is most famous for playing Princess Leia in George Lucas' "Star Wars" saga with this picture also being a science-fiction film.