Kill 100 zombies
Kill 500 zombies by headshot
Kill 50 zombies by combo
Complete 5 missions, without damage
Kill 20 acid zombies
Repair weapon 10 times
Fire in head 500 times in single mission
Kill 500 zombies by grenade
Achieve 10 level
Upgrade AK-47 to 2 level
Hold out in the time-out game type for 10 minutes