All Scientists must survive 10 waves in a row
Kill 300 zombies using the explosive barrel
Close 100 doors
See the Game Over screen for the first time
Survive the first wave
Freeze 200 zombies
Buy the Gatling gun guard
Kill 100 zombies in one game
Kill 1000 zombies in one game
Kill 30 zombies in one game
Place 500 Handgun guards
Place 500 Rifle guards
Place 999 Guards
Reach 3000 supplies in one game
Repair 30 doors
Buy the Rocket Launcher guard
Buy the Shotgun guard
Buy the Sniper guard
Survive 30 waves in a row
52876
2772
1476
24341