Here is the full list of all 12 Dead Days achievements.
Kill 100 zombies.
Kill 500 zombies.
Kill 50 special zombies.
Reach level 11.
Reach level 22.
Kill 100 zombies with a pistol.
Kill 100 zombies with an SMG.
Kill 100 zombies with a rifle.
Kill 100 zombies with a shotgun.
Walk 200 metres
Walk 2000 metres
Walk 20000 metres