Make 3 flips
Kill 2 birds
Get 3 stars at one level
Complete the level
Buy a sticker
Fully upgrade your car
Kill 1000 zombies
Kill 800 zombies
Kill 600 zombies
Die 2 times
Earn 1000 points
Kill 400 zombies
Kill 200 zombies
Buy a gun
Unlock your first car
Complete tutorial