Ok, still haven't played the game game, only MP but it is fun. It's definately different but not in a bad way. There are some new MP games you can do along with the old ones.
I haven't unlocked many of the guns but the ones I have are all kind of the same. The rifles/sub machine guns etc.
The perks aren't all that exciting basically the same.
Kind of cool you can jump into tanks and drive them around kill people etc. In some of the games they are a big part of the strategy etc.
The maps are great. Very big, lots of places to hide wide open. The maps in general are much much better. I don't even know if I've played all of them.
I've logged a couple hours of playing time. need to play the actual game. I won't stop playing cod 4 either, they are different enough that I can play what I feel like.
