why would you even want to play that pathetic game ? I got bored with it after 5 minutes, it's way too old school, repetetive corridor crawl with monsters spawning from every hole which exist in the walls just for that purpose. And what does it add to the game that you constantly need to swap between the flashlight and shotgun, or that it takes 20 seconds to load that stupid weapon ? And the game's supposedly best feature, the graphics, is not really that good, I mean the engine might be newer (but not much better than quake 3), but the textures and objects are very plain, simple and boring. Add to that the constant darkness, and you just have a whole alien-1 movie like scenery which is not really impressive at all. You could argue it has atmosphere, but it really depends how many people like this kind of atmosphere.
So consider yourself lucky that you don't have to participate in the $55 ripp-off scam called doom-3