Played it for the first time half a year ago. It was good enough to play through, but it wouldn't make my best games ever list. I'd also say Stalker and FEAR are scarier/better.
Maybe the shadows were interesting for the time, but they aren't good by any stretch of the imagination. In real life, shadows aren't completely black. Holding your hand a foot over a piece of paper, so the paper is in the shadow, isn't going to make it so you can't even tell the paper is there.
Also, it was a bit annoying how they made a limitation of the game engine (ridiculously bad shadows) central to the "scare" mechanic (enemies are hiding in the shadows, in a lit room).