What it has going for it is the story and the horror/Lovecraft theme. It's mainly a stealth, puzzle game. You shouldn't buy it if you want a FPS action game. Although it is first person and there's combat in it, it deals with this aspect rather poorly. The enemy AI seems lacking, and the character animations aren't very good. In addition, enemies respawn and dead enemies fade out as soon as they hit the floor. This makes combat not much fun at all. Although I did quite like the injury and health system. If you take damage you must stop and heal yourself quickly or continue to deteriorate from blood loss.
An array of other niggles detract from enjoyment. For instance there's no quick save. Saves are handled by finding save points throughout the level. Your character moves so infuriatingly slowly, and his annoying voiceover ruins all suspense or spookiness. The insanity effects are just annoying and frustrating, especially when you're being chased by axe wielding maniacs and your vision gets all blurry and your movement slows down to a crawl because your hardened ex police detective is having a panic attack. And finally it's just seriously hard! There are extremely difficult little set pieces that you have to consult a walkthru or simply do over and over again until you figure out how to get through. They leave absolutely no margin for error! You'll be doing a lot of the game over and over again anyway because of the save point system.
It had potential, it's just a shame the devs shot themselves in the foot with so many things.