Here is a mega tip:
To win you must get Tank first. To get this destroy some cities in africa, then when you unlocked middle east, destroy or infect Baghdad, kill Rambo in Qahandar and Wallah! Tank kills, not infect, but strong and attacks with a shockwave.
Here is a strategy for noobs, kill a hero. Wait until a crowd gathers up and infect, mix the hero a few seconds after, if only a few survivors and no zombies, bomb them. Enjoy world domination!
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