Not that great but not that bad either. The plot is somehow both extremely simple and confusing at the same time, and it is halfway incoherent- something which is said about giallo as a whole, but unfortunately it's missing that trait which redeems other works with that same quality: beautiful visuals. Many (not all) gialli are style-over-substance; that is to say that the plot takes a backseat to the visuals and the atmosphere that bestows. They focus on gorgeous, luscious sets, artistic camerawork, and beautiful locations. Other gialli are tight thrillers, plot focused and over the top works that take hitchock and amplify his tendencies to the 10th degree, creating a campy but coherent 70s erotic murder mystery. This is unfortunately neither. It means to be plot focused, but doesn't do enough. The story is both simple and convoluted, there are things which aren't explained, and it's a slow burner without the atmosphere or visuals to justify that pacing. If you're looking for a giallo to watch you can do a whole lot better than this.
On the flipside, if, like me, you are a giallo fanatic and have eaten up all of the main dishes, this one isn't one you must avoid entirely. It still has enough there to scratch the itch, it isn't completely useless. It's enjoyable as a piece of camp with that giallo feel and the storyline isn't fully worthless, you'll still be interested to know what's happening.
On the flipside, if, like me, you are a giallo fanatic and have eaten up all of the main dishes, this one isn't one you must avoid entirely. It still has enough there to scratch the itch, it isn't completely useless. It's enjoyable as a piece of camp with that giallo feel and the storyline isn't fully worthless, you'll still be interested to know what's happening.