For me, the game did not work. Could not get emotionally invested in any of the characters, and even though I find the underlining idea of the story somewhat interesting -- Alan Wake just does not go anywhere with it.
Alan Wake does not qualify as a realistic story with a supernatural element. It is not valuable or compelling as a mental illness story. Too poorly thought out to be an interesting supernatural story.
It tries to dip in all of the above and ends up deciding on the last option.
And in that category it does not reach any hights, the story is rather primitive with a very blunt delivery. Light is good, darkness is bad, so click to turn on the lights.