Continuity mistake: In the original 1980 version, in the first wideshot of Darth Vader's Star Destroyer, the light of a Star Destroyer can be seen on the right side just flying through space. This is fixed in the 2004 DVD release.
Continuity mistake: In the art studio Richie is working on a painting and it only has a small part finished. In the next shot the painting is completely finished. (00:08:25)
Continuity mistake: When the windows on Nick's truck are smashed, Elizabeth has protective gloves on when she covers her face from the glass, they are then gone when the truck comes to a halt.
Continuity mistake: When Reeves signs the guest register at the hotel in 1912, his signature is different from the one that he saw in the register that he found in the attic.
Continuity mistake: When Superman starts playing hide and seek with the villains, he stands away from the icicles. When Ursa shows up a frame later, he's leaning against them.
Continuity mistake: In the bullfighting scene Herbie's driver-side running board is dented upward in the middle, but in the following scene it isn't there.
Continuity mistake: While Puma Man is flying away from the mansion and Kobras tries to take over his mind, Vadinho is in the grounds surrounding the mansion, quite a bit outside the city limits. However, when Puma Man crash lands downtown, Vadinho is in the same building, with no time to get there.
Continuity mistake: When Voltan barges into the convent with his men the nuns go from behind their individual pews to huddled in a group behind the Abbess between shots. (00:11:06)