Why was this a series though ? It was more like a director's cut of a movie than it was a series. In fact, it felt like the sequel of a movie that hasn't been released.

The biggest drawback of this is the fact that the series begins from the middle of the story. All the characters are introduced straight away and you're expected to know the backstory. If I hadn't read the synopsis before I had started, this would've been even more confusing than it already was.
In addition to being confusing, because I couldn't figure out what exactly were the motivations and interests of each character, the episodes were a little slow. Watching them do things they have reasons to do, but not knowing what they are, is frustrating.
The last episode did clear some things up, but I was left wanting more. Especially more backstory, since this wasn't a case where the mysterious happenings will have a proper explanation, no, the story here just happened.

The action sequences were pretty good, full of violence and gore, as expected from the director after The Witch. Same goes for the acting, four episodes isn't a long amount of time to set up a plot and character development, but most of the actors did a great job.

But for audiences sake, BRIGHTEN YOUR PRODUCTIONS! Seriously, increase the brightness of your screen while watching because I couldn't see half of it no matter how much I increased the brightness.

It isn't necessary to watch The Witch (either movies) because this can be watched as a stand alone series, but there were a couple of references to some characters and storylines from the movies. I would be curious to see if and how they can bring all these stories together, because albeit confusing, the premise is interesting.