William Katt said that at the start of the series, he and Robert Culp had difficulties getting along and working with each other. Katt added they were able to use that to their advantage, as their relationship reflected the one portrayed between their respective characters. Katt and Culp were able to resolve their differences, and actually became good friends over the course of the series.
William Katt's real-life mother, Barbara Hale, played Ralph's mother Paula Hinkley in the second-season episode "Who's Woo in America".
ABC officially canceled the series before the last four produced episodes were aired. The "lost episodes" were sold along with the rest of the series as part of its package for syndication, and later DVD collections.
The show's theme song was sung by Joey Scarbury and released as a single, which peaked at #2 on the Billboard charts during the summer of 1981.
Although DC Comics tried to sue the producers for copying Superman, the show's premise is closer to that of another DC Comics character, Green Lantern, who was given a power ring by an alien to become a superhero.