When introduced by the father, he introduces Jenny and Steve, his right to left. Jenny is to his left, so he should have either introduced Jenny and Steve, his left to right OR Steve and Jenny, his right to left.
Obvious use of a badly-made puppet cat who is smoking when things begin to go haywire in the kitchen.
After having Nathan pick the lock to let Jenny back inside. Jenny shuts the door and the door handle falls off, when "Priscilla" arrives a few minutes later the handle is back on the door.
When Sam is first seen watching his game shows while talking to Jenny in a darkened room, it is painfully obvious colored lights are being turned on and off in the room to simulate the flickering light of the color television.
Steve and Sam have the same last name but Sam is Jenny's father, not Steve's.
Man pretending to be gardener mutilates hedge with electric chainsaw while soundtrack is of gasoline chainsaw.