I dont know, I downloaded the game and I'm not able to play without a valid cd-key. I'm going to read up some reviews to see how the multiplayer is like, if it's any good and alot of people start playing it I'm just going to buy the game, because I did enjoy the singleplayer game, even though it was very short and the enemies get a bit repetitive towards the end. (took me approximatly 7 hours).

Even though it's enjoyable, IMO the game isnt worth buying for the singleplayer alone. Or at least not until the price has dropped.