System specification and information if it's a laptop or a desktop computer would be very handy in this situation. We cannot do much about this issue without knowng your system specification.
For now, as jjsimp suggested, you may visit Alan Wake Forums and search for a simmilar issue.
I may also suggest visiting PCGamingWiki. It's a great source of information about PC games and various problems with them.
On PCGamingWiki, there's a page for Alan Wake, you can visit it, make sure the system requirements are met. Also, there are some fixes for some problems posted on that page, for example, low frame rate and stuttering.
Post edited June 22, 2013 by defosh369