Defending missions need patched, the line needs to be moved back, often they will technically walk through the line but I will still kill them before they get off screen.
I really hate that most the game is on the various phones. I don't have one of those ipad iphone robot things w/e they are called nowadays. I just have a simple phone used for calling people. Really pisses me off that you can't play it unless you have one of those -_-
It needs more money dumps, I had all the upgrades around the destruction of canada, then I was just rolling in millions of dollars afterwards, had fully upgraded zombies and all :/ It needs a endless upgrade, perhaps a small boost to zombie stats or something.