Underrated

I love slasher films and gialli and this is a nice hybrid of both. It IS slow, and the killer's singing IS so annoying, but what it does have going for it it has a lot of. Absolutely beautiful cinematography, very atmospheric. You can tell it's an Italian production. Trish Everly is lovely too, a shame she didn't do anything else. Good, strange Italian music score, I liked the opening credits sequence too. I also thought Mary was really creepy too, and her "twins again" speech was scary. I liked how violent the ending was and the first time i saw this, I jumped at the very ending. I definitely see it's flaws, and it has many. But it's got such a good aesthetic quality alone that to me it deserves a watch.