SPOILERS AHEAD: Woah, what a terrible movie. I am literally unable to think why someone would like it. My theory is: You need to be someone who truly believes that there's a deeper level of evil than all of the violence, torture and death we see throughout the film, and just then, you can actually be disturbed by it. Like if all those things were barely scratching the surface of whatever hell was unleashed after the evil "won" at the end. The concept had soooo much potential but it ultimately fell short by the imagination of Demián Rugna, in fact, I think that's why his script never really told us what happened when the evil won, he simply cannot fathom that deeper level of atrocity.
Great things: Cinematography, special effects, some of the acting, a fresh (??) concept and locations.
Bad things: About everything else. The music, some of the acting, the script, the storyline.