Call of duty is just so cool because it has better guns,graphics,levels, and it go's from everything coming off to real life action.mainly just a hardcore game that you would ever have.zombie level the best unlocked level ever!
your in a house with your freinds all alone trying to stop an army of the dead.
non-stop zombies,level of zombie dogs, and jaggurnaut zombies.
all of this with some online hardcore action.
from teamdeathmatch to hardcore temdeathmatch call of duty world at war has everything.they also have a company that cares about thier players with cool updates and double xp weekends for no reason at all.