The First time my friends and In watched He Kills Night After Night we had no idea what was going on. There is a bit of a mystery involved as to the true identity he who kills night after night. Every time we watched it after we knew exactly what was going on, and the movie just got better and better.
I have to admit that i love this movie. It has some of the best dialog, and one liners. When we watch it now, we just giggle at it. The best part about the whole thing is when the plot elements finally come together it goes so far over the top that your jaw just drops.
It tries to be a morality tale against the loose sexual climate of swinging seventies London. So give it credit for at least trying to have an ultimate point. That might just be an excuse to have a slasher movie, like any reaction will do to justify a good horror/mystery movie. The bad guys always feels justified in his motives, no matter how far out they may be.
So that being said, I would recommend this movie to anyone. not everyone might understand it at first, but if you watch it a few times, it gets better and better.