Good, but not great
I by no means found Alan Wake to be a bad game, it's got a fairly unique and interesting story, and some solid gameplay that generally consists of some pretty tense walks through dark forests where you have to use the combination of your flashlight and pistol to take down enemies.
The big problem with the game is variety, at one point in the game, you kind of have to defend a spot against zombies, and another you're just using the flashlight while an NPC does the shooting, but these varied sequences are way to few and far between. The story, which usually gives you a reason to keep going in the game can get tiresome at times as well, as it seems almost every single cut scene is just kind of set up or an excuse to get you back in a dark forest, where the gameplay seems to repeat itself again.
What I'd say is that if your a fan of games like Silent Hill, and can put up with repetitive gameplay for the sake of a story, then check it out...otherwise I don't believe you're missing out on too much here.