Halloween II

The mask Michael wears is the exact same mask (a repainted and modified Captain Kirk mask) worn in the original Halloween (1978) film. It looks different in the sequel because the paint had faded due to a few reasons, first because Nick Castle, the original Michael, kept it in his back pocket during shoots. Also, Debra Hill kept the mask under her bed for several years until the filming of Halloween II, causing it to collect dust and yellow because Hill was a heavy smoker. Also, the mask appears wider because Dick Warlock is shorter and stockier than Nick Castle, so the mask fit his head differently. As the producers thought it would be the final sequel in the series, they let Warlock keep the mask, scalpel, boots, jumpsuit, and knife used in filming. When they decided to revive Michael in Halloween 4: The Return of Michael Myers (1988), the producers realized they had made a mistake and never again gave props out to the cast and crew, therefore subsequent sequels used different masks that looked rather different.

(at around 2 mins) In Halloween (1978), Michael falls off the back balcony of the Doyle house, however in this film he falls off the front balcony. The balcony in the first movie is a covered balcony, the balcony in this film is not.

Michael Myers (age 23) is listed in the ending credits. The film takes place in 1978 when Michael Myers is 21 years old, which is also stated by Dr. Loomis in the movie.

The gruesome shot where a nurse gets a syringe in her temple was toned down in the German version. This however didn't stop the censors from banning the film.

Edited from Halloween (1978)