Continuity mistake: After Nicky has been separated from her parents, Nicky and her father are walking the streets looking for each other. A horse and cart with lots of children on the cart and a line of children walking behind it goes past Nicky. She sees her father walking on the other side on the road, but when she walks behind the cart to cross the road, the camera angle changes, and the children have changed places in the line.
Continuity mistake: After he has destroyed the television Mr Gore tries to light his pipe. If you look outside you can see several cars parked outside the Gore's house, in the following scenes outside this house all the cars have gone. They couldn't have been driven after "the changes" had started.