Sally Jane Black’s review published on Letterboxd :
Sumptuous is probably overused, especially when describing things that are either Gothic or giallo, but this is both. It earns the designation, from the architectural porn to the high fashion (interwoven into character, setting, and plot) to the long hallways and tight interiors to the wallpaper, yes, the glorious, sometimes garish, sometimes sublime wallpaper. By god, what wallpaper. (I love the wallpaper.)
As a murder mystery, it uses the "kill the suspects" model, especially toward the end, a sort of lurid Agatha Christie story with a supernatural twist and grotesque secrets. But giallo is not entirely about the plot; someone is being killed and someone is killing. Like the blunter cousins in the slasher genre, these films are sometimes more enjoyable when they cling to the formula. Sometimes, they add enough window dressing or herbs and spices to mask the formula, and sometimes, they just go bananas. This feels like a formula giallo with a dash of spice, and it's one of the good ones. (For one thing, it keeps the major suspects alive fairly late into the game, at least keeping up a touch of suspense that way.)
But really, gialli are divine because they look good. This felt like a Hammer giallo in the way it used location and tone, but it looked like Italian Gothic in sensual appeal, striking framing, kaleidoscopic camera work, and a bottle of J&B.