Here is the full list of all 12 All Zombies Must Die! achievements.
Complete "Return to the Military Base"
Complete "Dev Card Hunt"
Fully upgrade a weapon with any status effect
Complete ALL character quests
Complete a base quest without taking any damage
Witness Luxo joining the group
Witness Brian joining the group
Witness Rachel joining the group
Kill 500 Zombies in one level
Use your first Smart Bomb
Kill a Mutant with your fists
Kill a Zombie