There should definitely be a badge for getting gold on all of the levels. It's super easy to kill everyone in 20 turns but not so much to get them in 1 turn each.
The game glitched when I was heading back to the subway from Union Security. I couldn't move and I was flooded by zombies coming from the side of the screen I was nearest to. There's only so much you can do with a hatchet...
 "Gravitee Wars"){kind=icon}
 "The Last Stand: Union City"){kind=icon}
 "Pretentious Game"){kind=icon}