Alan Wake is best described as "already seen it all". Storyline has enormous potential but uses only 20%.
I mean, story is very well created and the idea is great but it's ruined by unvaried game play. Jumping between few storylines isn't just enough.
Graphics and audio effects are very good, 9/10 I would say. From my point of view Alan Wake is definitely not worth buying. Maybe it's because of my huge expectations before this game came out, I don't know, but I can only judge from what I experienced while playing it.