Amuck! has the strongest Jess Franco vibes of any giallo I've seen. Specifically, it has enormous narrative, attitudinal, and thematic overlap with 1970's Eugenie, another film about a young woman being introduced into a dark world of sex and violence against her will (and under the influence of drugs), and developing a dangerous curiosity about that world.
Neither film, unfortunately, is particularly interested in genuinely examining why that fascination occurs, or what the women in question are seeking with their tentative, voluntary engagement, preferring instead to focus on the spectacle of the sex itself. Which, honestly, is fair enough. When you've got both Barbara Bouchet and Rosalba Neri in your movie, you'd have to be a fool not to have…