The acting is solid, and the script holds tight. It does enough with the character dramas to keep the lost-in-the-woods story dynamics moving forward, even throwing psychological shade over fractured mindsets when the good-hearted bickering turns harmfully personal. I didn't think it always worked, but it gave the story an extra dimension to squeeze out the emotional tension, provide motivations and the ability to show this creature can mentally manipulate the minds of those it stalks.
Another element working to its favour was the dark, sprawling mountainous forest becoming a character in itself. The way the camera captures the surroundings and how the audio picks up on the creature moving through the lush vegetation (branches snapping to the off-screen growling) gives off a spooky ambiance that at anytime can swallow you up, or inflict a gruesome surprise. As for the monster (an ancient evil), I actually liked the Norse old-world folklore and unique camouflage design whenever we got the chance to see it. This does come to fruition in the outlandish descent of its third act, where I think it loses a bit something when it breaks out. The creature is mainly brought across in CGI, and done so perfectly, although there were practical prosthetics when it got up, close and personal, and the latter when used I found downright effective.