Dumb fun - Quirky production and obvious acting and script flaws. This sort of goes all over the place, and I rather would've gone without the porno film shots shown on the TV set to substitute for no actual nudity/sex between the characters themselves. I find that odd but also a different thing in film that they did this, so whatever.
Becomes increasingly convoluted until the end pay off is not as good as it could have been or should be. It just does not make sense why there was that extra part to the backstory explaining the killer's motive/s which throws the viewer off the main reasons.