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 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.
Owing to legal complications, the archive footage come from Batman: The Movie (1966), not from Batman (1966).