It's unofficially based on Ira Levin's A Kiss Before Dying (1953). There's a Shakespeare influence, too, and even some violent giallo-esque kills. It's a strange mix that doesn't always work, but when it does it's spectacular.
It would make a tremendously powerful two hour film. I realise that to achieve that would mean losing a significant amount of footage, but it'd be just about doable. I'd begin by chopping most of the 'comedic' head servant's scenes.
3½ gamely gambles out of 5