Covered Up: The theme song "Original Sin" was originally the title track for a Pandora's Box album written and produced by Jim Steinman and was later more famously covered by his frequent collaborator Meat Loaf (with some lyrical alterations: only the movie version features lines about "who knows what evil lurks in the hearts of men").
What Could Have Been: The shooting script had a longer chase scene in the Hall of Mirrors, including flashbacks and banter. However, an earthquake destroyed some of the mirrors, making the full scene too expensive.
Sam Raimi wanted to follow up Evil Dead 2 with this but was unable to get the rights. Instead, he directed Darkman, using some of the ideas he had for his version of the story.
The Other Darrin: Tim Kitzrow provides the voice for Lamont Cranston/The Shadow, though Baldwin's speech from the film itself appears as well.