Nothing supernatural, and completely implausible
Whole post is spoilers if you have not seen the film.
This was awful, and semi-incoherent. It felt like the film was being made-up as they went.
Somehow Max is everywhere they choose to stop the car, already waiting for them ... and apparently on foot. Further, he is some sort of ninja, touching people/closing doors/etc. and vanishing from sight within seconds.
How on earth does the pub tie into the story, when the Hotel reservations were made before they ever arrived? He didn't make them at the Pub, because he had full color pages he had printed out himself, waiting in the glove-box when they left.
How does a single man cut down a tree that size in about 90 seconds? And how does he do it without a lot of noise?
There was nothing scary, suspenseful, or tense in this film because every scene felt 100% arbitrary. It looked more like someone trying to film a collection of random scenes they felt would be frightening rather than an actual film.
No suspension of disbelief = No horror.