What Could Have Been: The original plan for Zee's death was to have Gill Man throw him towards the screen, which would have made for perfect 3D fodder. Malfunctioning equipment forced the makers to abandon it.
Trivia for the pinball machine:
Cut Song: "At the Hop" was to have been included as one of the songs, but it was removed from the final version, as it was too cost prohibitive. The voice clips for the song can be found via PinMAME.
The "Joe's Diner" mode from The Flintstones has a similar premise; instead of an irate moviegoer at a drive-in, it's an impatient drive-thru customer at a drive-thru. The exact same animation of the guy shouting "MOVE YOUR CAR!" (minus the drive-in setting, obviously) was recycled for this new mode.