The movie is really a psychological thriller. It is not filled with gore and maniacal killers like Michael Meyers, but it keeps you guessing what is going on. There is no clear cut ending that exactly spells out what is going on. I think the actors do a really good job. Because it is psychological it moves slow so that the plot and character development can happen. You need to be in the right mood. Hard to believe based on a book from 1957.
SPOILER ALERT:
I do not think the husband is making anything up and I do not think she is unaware. It is a really morally warped game. I also think there is a lot of love between them “Natural Born Killers” style love.