I'm not too far into it yet. The graphics are pretty amazing, as well as the audio (play wearing headphones...omg).
It plays kinda like an updated Soul Reaver, where there is combat and puzzles to solve to progress. My only complaint is the camera, so far, but I understand why its locked to just behind and over her shoulder. So far the puzzles involve seeing runes, and having to find them represented in the environment to unlock them. Some puzzles are a matter of timing to get out of an area. There is perma death of a sort. In the beginning she gets infected with a dark force, kinda like Evil Dead (it got into my arm...). Every time you die it spreads up her arm, and if you die often enough for it to spread to her head, the game ends and you lose all progress. There are save points you run across, that are automatic upon reaching a new area. So far it's fun, but it's definitely a niche game.
I would recommend it :)