Sometimes a book comes along where I'm convinced it is either horrible or amazing and I vacillate between the two. Typically the process ends on horrible as the uncertainty in and of itself signals to me something being wrong. Ice has this quality, but came out on the other side. I'm not going to say it was amazing, but it squarely lives in the good camp.
At times I had no idea what was going on. Was he dreaming? Was I reading a nonlinear narrative where what I was reading just was going to happen in the future? The past? I am now of the opinion that when these situations arose I was being let inside the narrator's mind, part fantasy, part memory. We never really are shown the full picture, maybe he does not even know the whole picture himself. There is so much left unsaid that your imagination is left to do much of the dirty work.
Horror movies that really stand the test of time tend to eschew the in your face motif that has become so prevalent lately. If I can see the monster then while maybe scary today, it is unlikely to be scary in the future. The unseen can always be more timely and powerful when done well because your mind fills in the gaps. It is a personal form for terror. Much of Ice used this technique to let your mind do some work. This was not always successful. Frequently this felt redundant. There was quite a bit where you were seemingly supposed to imagine something but it was the fifth time you heard about it so it was no longer suprising that you were not being told more.
For a short book, it took me a little while to read because it was complex. Luckily it was short, any longer and I don't think I could have really kept what was happening fully in my head. I recommend this one if you want a strange, but quick read. As to genre, it is supposedly science fiction, but I have never read anything like it. Genre defying gets thrown around, but it may just fit here.