Movies, just like paintings, were quite the source of inspiration for Sine Requie: Snake Eyes. Many plot elements and characters have been influenced by Italian horror movies from the 70s, such as Dario Argento's "Profondo Rosso" and "Suspiria" along with Pupi Avati's "La Casa Dalle Finestre Che Ridono", on which the map for Sant'Ezechiele was based (this is the village visited during the demo). The picture below shows the character Don Avati alongside the priest from "La Casa Dalle Finestre Che Ridono" played by Eugene Walter.

The game's soundtrack was inspired by legendary master Ennio Morricone, especially the tense duels from "A Fistful of Dollars" and "The Good, The Bad and The Ugly" which you can find in the video below

And here's the music from Sine Requie Snake Eyes
https://soundcloud.com/luca-bellini-839032297/faces-of-evil