Just start the game
Survive the lobby
Survive level 1
Survive level 2
Survive level 3
Survive level 4
Survive level 5
Survive level 6
Survive level 7
Survive level 8
Survive level 9
Survive level 10
Survive level 11
Survive level 12
Survive level 13
Survive level 14
Survive level 15
Survive level 16
Survive level 17
Survive level 18
Survive level 19
Survive level 20
Survive level 21
Survive level 22
Survive level 23
Survive level 24
Survive level 25
Kill 10,000 zombies
Kill 5,000 zombies
Kill 2,500 zombies
Kill 1,000 zombies
Kill 100 zombies
Kill 500 zombies