Alan Wake is Xbox 360 exclusive
Wednesday, July 15, 2009
Nowadays, “exclusive” also often means on PC as well – but not this time. Despite being “exclusive to the Xbox 360″ before, it’s now really really exclusive in that PC players won’t be getting it because “joint PC/Xbox launch is not possible at this late stage” according to the game’s writer Sam Lake, even though it has been delayed over and over.
However, he did also state that a PC launch could be possible in the future, but it would be up to their publisher, Microsoft, to make the call.
Source: DigitalSpy (Thanks, Redrum!)

