I just noticed a post where someone bought the game on Direct2Drive. This is a bad mistake, as they have slow patches and an install limit. Buy the game on steam.
Just to preempt the general F.U.D. about steam, it has an offline mode, so you can play installed games without an Internet connection.
http://www.steampowered.com/v/index.php?area=game&AppId=8800&cc=US
Just to preempt the general F.U.D. about steam, it has an offline mode, so you can play installed games without an Internet connection.
http://www.steampowered.com/v/index.php?area=game&AppId=8800&cc=US