Here is the full list of all 10 #KILLALLZOMBIES achievements.
Do not shoot for 6 minutes
Earn 10.000.000 experience points in a session
Kill first undead boss
Perform Rampage attack
Use melee attack 100 times in a session
Stay live atleast 60 minutes
Crash atleast 100 cars in one session
Rack up to 30th level
Kill 500.000 zombies
Kill atleast 1.000 zombies with each weapon type