The knife Charles Lee Ray uses during the flashback sequence is the same knife Chucky uses throughout the first Child's Play movie.
The makers had a practical joke at a bus stop to promote the film. A billboard of the movie's poster would light up and an actor dressed as Chucky would suddenly bust through the billboard and scare whoever was nearby.
According to Brad Dourif, he had to wear a wig and massive amounts of make up to make him look like he did in the original Child's Play (1988) movie. Lighting was also a huge factor.
The actress who plays Nica, Fiona Dourif is the real life daughter of Brad Dourif, who provides the voice of Chucky.