Unlock all epic characters
Play the game for 5 consecutive days
Use revive 50 times
Use free gift 20 times
Try out 3 characters in special offer
Share a screenshot once on facebook
Complete 5 daily missions
Hit a max combo of 25
Use Facebook connect
Kill with each environmental obstacle
Survive for 20 seconds without killing a zombie
Overtake a friend on the leaderboard
Die under 5 seconds
Play 100 games with a single character
Get 1000 kills in one session
Claim all 28 daily rewards
Unlock all common characters
Upgrade any character to max level
Unlock all rare characters
Complete all quests