Crazy City:Zombie Survival

Start a population, zombies go!
Infect scattered populations on the streets;
To breach the fortifications established by the inhabitants;
Active search than their own weak zombie head, kill his small army;
Then you'll find you can walk sideways through the city!

If you just want to be a Buddha zombie, do not want to disturb human life, do not want to risk the human defense points, and dare not compete with the same kind of competition, then hope you can run fast enough and know the terrain, so that you can avoid double or even triple attack!
Good luck!