Revealing mistake: The sliding door to the bedroom in Simonson's apartment appears to be covered with a sheet of 'bubble wrap' in early scenes of the room.
Revealing mistake: Near the beginning, Megalon steps out from behind a mountain. It's obvious the "mountain" is a cardboard cutout.
Revealing mistake: Diane Keaton's stunt double is obviously a man during the scene where Luna swings across the stream and into a tree.