Happy nightmares, dearies...
I'll keep this brief: this game was made to terrify you. No, it's not a hyperbole. It's true. The sanity effects of the game, as well as the changes in the atmosphere either keeps you on your toes or scares you away from the game for good. To make matters worse, the game is based on some of Lovecraft's works, which gives you another hint at what the game is like. All in all, this is what psychological horror should be.
Now if you will excuse me, I have another exorcism to preform on my Game Cube