there are probably only like, 1.5 people who dont know this, lol but it took me a while to figure it out-if you want to buy pacifist and antagonist upgrades, you need to buy the first one of either, and use that upgrade to kill people as much as you can, then you can end up buying the upgrades with (+20) and stuff
Infectonator: World Dominator: This is how you get the special zombies. Do what is shown here and you will be unstoppable! Mwahaha! MJ - Destroy the grave in Jamaica ''Easier to use the bomb'' [Mexico] Tank- Kill Rambo in Qandahar [Middle East] Boomer Santa- Kill Santa in Nuunok [Greenland] Col. Sanders- Kill him in Kentucky [America] Ronald Mcdonald- Kill him in London [Europe] [can be found in other places] Venom- Kill Spiderman in New York [America]
 "Mass Attack"){kind=icon}
 "Polygonal Fury"){kind=icon}
 "Doodle God"){kind=icon}
 "Pixel Purge"){kind=icon}
 "Obey the Game"){kind=icon}
 "Super Crazy Guitar Maniac Deluxe 2"){kind=icon}
 "Pillage the Village"){kind=icon}
 "Hello Worlds!"){kind=icon}
 "Garden TD"){kind=icon}
 "Swords and Sandals Crusader"){kind=icon}
 "Talesworth Arena: Death Watch"){kind=icon}
 "Super Crazy Guitar Maniac Deluxe 3"){kind=icon}