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.
The scene where Chucky locks Alice in the closet and uses the F word, Alice tells Chucky to stop cursing, which his similar to Child's Play 3 where after his attempt to possess Tyler fails Chucky says The S word and Tyler tells him to stop swearing.
When Nica and Jiil are discussing where the doll came from. Jill says that she doesn't care if Chucky came from the Manson family, According to Don Mancicni Chucky's full name Charles Lee Ray came from three real life killers, Charles Manson, Lee Harvey Oswald, and James Earl Ray,
The trivia items below may give away important plot points.
During the scene after the credits in Andy's apartment, a photo of Kyle, the woman who helps defeat Chucky from Childs Play 2, can be seen next to a certificate from the military school Andy attended in Childs Play 3 and next to that is the original photo of Andy and his mother from the first movie.
This marks the return of original protaganist Andy Barclay. Alex Vincent played Andy in Child's Play and Child's Play 2. He was featured in archive footage in Child's Play 3 as a child, but portrayed as a teenager in that film by Justin Whalin. Andy is referenced in the beginning of Bride of Chucky in a newspaper article and referenced in commentary by Chucky in Seed of Chucky.
Though not seen, Andy's mother is mentioned by Andy and it is assumed she is either married or in a relationship with Mike Norris, who is also mentioned. It is also implied that Karen got cleared between the second film and this one.
The original Rated version of the film (which also serves as the TV edition) marks the only time in the entire series that Chucky is alive at the end of the movie. In all previous films Chucky was always dispatched by his adversaries in the finale. However the Unrated Cut includes an extra scene after the credits. In the post-credits scene (which is set 6 months after the canonical ending) the events are retconned and the tradition is maintained.
This movie has several moments that pay homage to the original Child's Play film one being that when Nica cuts his head off Chucky's body reassembles himself and he begins to attack again. Also the final scenes with Chucky and Alice, the scene with the police officer and Tiffany, etc.
When Jill is being electrocuted, the burning that takes place on her face is around her right eye- mirroring the damage Chucky had shown around his in the previous two films; then later in this film, when it's discovered that this "new & clean" Chucky doll has used prosthetics to cover the damage he's incurred over the film series.