Owing to legal complications, the archive footage come from the spin-off feature film, not from the TV series.
Due to copyright and trademark issues, the costumes worn were slightly modified from their original designs. For example, Batman's gloves now have 4 spikes rather than the original 3.
The series' first Catwoman, Julie Newmar, appears in the movie. Lee Meriwether's (Catwoman in the Batman: The Movie (1966) feature film) daughter was Julie's stuntwoman in 'Return to the Batcave'.
The scene where young Robin drives up to the gate and the car stalls was not scripted. Apparently, Jason Marsden didn't know how to drive a stick shift. It was so funny that the producers decided to leave it in the movie.