well ive only been able to play off-line in the single player mode, i havent been able to get the cd key to work, for some reason, the one that came with it is not working. the single player mode is just about the same as the original, same graphics.
You are running steam right? If so, why not call their support line? If the key doesn't work, they should fix it or give you a new one. Also, try going to the steampowered.com forums. There's techs there that can help with it.