Now onto the Single player mode or the «single player
upgrade» if you've purchased the multiplayer edition, this is basically the same as a private match in multiplayer, you play one of the multiplayer selections against AI on top of that you have survival mode which was rather confusing, my idea of the game was a normal FPS game with zombies implemented so you can't camp, when you're playing the survival mode the full area has some sort of gas which will kill you if you don't get out of it, you get sent to different air pockets which open up in a set area
per round, this meaning you have to camp in the air bubble and take on the hordes of zombies approaching, I've played a few zombie fps games in my days and always wanted to move around, create a train and take them out, on top of that ammo drops or
weapon drops are in said bubbles and lack in quality, I wasn't impressed with the survival mode implementation and wouldn't advise any horde fans to even look at it.
This can be done with hundreds / thousands of
weapons per weapon, so once you get a
weapon you like, you can use all other
weapons for that character to keep
upgrading it and essentially never having to buy new
weapons unless the new
weapons outclass your
upgraded weapon (which can then be used to give your new
weapon a major boost).