Giallos - you either like them or you don't. And the same is true for this right here. It does cut deep - no pun intended and meant as a nod - homage or whatever else you want to call it. This is fan service of sorts. The movie really checks all the boxes, from the whodunnit, to the nudity, to the violence, to the insane twists after twist towards the end ... well you will not be dissapointed if that was floating your boat.
You may be surprised to hear or see that this was made in 2018, especially because it really does its best to look old ... to look "bad". So all that in purpose - hopefully something that is good for you. If you are not a fan of Giallo I would suggest not watching this. Because this will have the same things you hate about those movies (genre if you want to call it that).
Otherwise sit back, relax and let the movie take you on a ride ... no brownie points if you guessed the big twist ...