Stepping back from the theme of Halloween for a moment, I want to discuss the principles of what makes a movie, beyond genre, great; are there any universal traits shared across genres? I would absolutely agree that there are, and I intend to phrase some of them within the review of this movie.
One of the things I think great movies usually do very well is build up the suspense in a way that, when something significantly changes the focus, it hits home and your body has a notable reaction; that's why people always return no matter how scary or tense it may be to them (which is fantastic, by the way!). This movie does that in a rather unique way, it doesn't double-down on excessive gore, and it doesn't express anything for the sake of raw brutality; it goes in the opposite direction by contextually framing everything, with fastidious timing.
The other aspect that makes this movie great is the fact that it is based on Basque folklore, with Basque options for audio and subtitles. For my money, the audio has to be in Basque because it adds that unique flavour that makes every language great; within the first ten minutes I had my first, and without a doubt, hands-down favourite quote: 'Sinesten al duzue infernuan' Roughly translated as 'Do you believe in Hell?'
Here's the trailer, let me know what you think!
Enjoy, and Happy Halloween! ;)