Finally! I'm only on the second level, but...WOW. What an amazing game! The graphics, while they seem like they would be bland and distasteful, are actually visually stunning. The sound is great, along with the voice acting, but the music could use some help. Most of the time, you can't even hear it, and when you do, it is too simple to add anything to the mood.
The gameplay is very unique, and the game does not have a definite genre. It is a mix of a rail shooter, an FPS, an adventure game, a puzzle game, a survival horror, and even has a few RPG elements thrown in. You cannot really control your character's movement, but instead you just press the A button, and he runs down the hall, where you can choose which direction to go next. If you hear the laughter of a Heaven Smile, you have to whip out your gun (different characters have different guns), and either blast away, or take your time and aim for their weak spot.
I won't spoil much of the story, but at the beginning of the game, you figure that the story is pretty much, go to that place, and kill that guy. Oh, and kill anybody that gets in your way. But, as the game progresses, you see that it is much more than that. While only a fraction of the game has yet to unfold to me, I am already intrigued.
All in all, buy this game. I think that Greg Kasavin summed it up well: "You're often left wondering just what the Hell is going on...this is a love it or hate it game."