Beat 10 levels against Hard AI
Beat 10 levels against Normal or Hard AI
Beat 50 levels against Hard AI
Beat 50 levels against Normal or Hard AI
Start beating the AI
Complete Chapter 1
Complete Chapter 2
Complete Chapter 3
Complete Pawn of the Dead
Capture/infect the enemy AI Queen (without seeing solution) (the first move doesn't count)
Score 50 in Queen vs Zombies Mode