Continuity mistake: The Myers house was a small Victorian house in all the other films, but in this one it's a huge gothic mansion.
Continuity mistake: When Michael Myers is chasing Billy at the farm in the car, his position changes as he is driving - he is on the passenger side several times then on the driver side.
Continuity mistake: In the scene were Tina asks Michael to stop the car at the store he starts driving faster going at least 30mph for 7 seconds. When he finally stops and backs up he drives about 5-10mph and ends up outside the store in 4 seconds.
Continuity mistake: When Michael rams the pitchfork through Spitz, it is at the lower end of his back, nearer to his waist even. A few seconds later when Spitz's girlfriend comes at Michael with the same pitchfork, some other shots of the now dead Spitz show the pitchfork holes up near his shoulder blades, probably 6-8 inches higher than where they should be.
Continuity mistake: The mask Michael wears when he comes out of the mineshaft is not the one he was wearing when he entered, the lips are different.
Continuity mistake: When Sam is with her boyfriend in the barn, she takes off her gloves twice.
Continuity mistake: Tina's hairstyle changes from at the party to when she's in the barn with Sam. It goes from a bun to a ponytail.
Continuity mistake: When Sam is in the barn holding a kitten, she has a make up design on her cheek. When she fights with Michael, it's gone.