GTA: Infectonator 2
You own a company that makes biological weapon. Your company has created the ultimate virus as it can turn people into zombies. Terrorists bought some viruses from you and you make even more money when the virus killed more people. The game is played with a mouse and you need to infect people with the virus. As you kill more people, you earn more. You can upgrade the virus in the lab for better infection. You can choose which country would you want to infect. You can go back to the same country over and over again till you are able to generate enough income to upgrade the virus.