Although it's sometimes listed as a giallo, this film is probably better describes as a Shakespearean Thriller.
It's all about the characters, their interactions, and their relationships. It's a drama. And sometimes, a melodrama.
Within the first few minutes of the film, we learn that Angela McDonald, Roberto Bisacco, and Anna Gaël are plotting something against Chris Avram. There are political elements of the bourgeoisie and proletariat. There is also some Freudian stuff thrown in for good measure. Of note, there is little violence to speak of.
I loved the 1960's rock soundtrack! It was surprisingly memorable.
It's a different kind of a film, and it may stick with you for that reason. However, it's hard to imagine the audience who would love this movie. It's too sleazy to appeal to fans of drama, and it's too talky to appeal to fans of thrillers/slashers.