The writing and experience was quite good but the VFX were pretty mediocre. It didn't have a lot of VFX which is fine but what was there was pretty unconvincing and distracted from what was supposed to be a convincing threat. For the little screen time you actually see of the wolves, they could have just used real animals. Had the wolves been treated in the same manner as those in GOT,(real animals increased in size through various film tricks) it would have made for a much more frightening experience.