Unlock Plague Types
Hidden Plague - Beat ALL 8 Plague types on Brutal Difficulty.
Immune Plague - Beat ALL 8 Plague types on Brutal Difficulty.
Unlimited Plague - Beat ALL 8 Plague types on Brutal Difficulty.
Bio-Weapon - Beat Nano-Virus Plague type on Normal or Brutal Difficulty, OR pay US$0.99 after unlocking Nano-Virus.
Fungus - Beat Virus Plague type on Normal or Brutal Difficulty, OR pay US$0.99 after unlocking Virus.
Nano-Virus - Beat Prion Plague type on Normal or Brutal Difficulty, OR pay US$0.99 after unlocking Prion.
Neurax Worm - Beat all 7 plague types on Brutal Difficulty only, OR pay US$1.99.
Parasite - Beat Fungus Plague type on Normal or Brutal Difficulty, OR pay US$0.99 after unlocking Fungus.
Prion - Beat Parasite Plague type on Normal or Brutal Difficulty, OR pay US$0.99 after unlocking Parasite.
Virus - Beat Bacteria Plague type on Normal or Brutal Difficulty, OR pay US$0.99.