Dont be to sudden on this, Until u play NMRiH.
Reason other zombie fps's dont make it right is mainly becuase of cheap software or the games just are not put into a realistic stand point.
Besides that, I'd like u to tell me how many u have played, becuase there are very few if any, and if there are any they are so low budget, of course they will be bad. So, we plan to change this!
But then again some people dont like fps zombie games. I accually prefer Resident Evil 4 style playing the best.
Good Luck with your MMO