Here is the full list of all 44 Dead Sky achievements.
Stop Sackhead with a bear trap
Kill a teammate with the afterblast of a demolition zombie that you shot.
Kill 6 enemies with the flamethrower within 8 seconds.
Kill all enemies in the Sewer on normal.
Kill 4 enemies in 3 seconds with the pistol
Die while reloading
Hit 3 enemies with a single railgun shot
Be the first one to die in a multiplayer game.
Heal 300 points of damage in a multiplayer game.
Heal 600 points of damage in a multiplayer game.
Heal 600 points of damage and kill 25 zombies with the rocket launcher in a multiplayer game.
Go 4 rounds without taking any damage and kill at least 40 zombies within that time.
Spend 200 scrap metal repairing teammates' turrets in a multiplayer game.
Have 5 turrets up simulatenously.
Kill 500 zombies with the berserker buff
Build 500 structures
Kill 3,000 enemies
Kill 6,500 enemies
Kill 20,000 enemies
Have the maximum number of defense items built simultaneously.
Survive a night without using your flashlight while still killing at least 10 enemies.
Take at least 250 points of damage in a single life.
Take at least 500 points of damage in a single life.
Kill 50 zombies using the Electro-shield upgrade in a single game.
Hit 5 enemies with a single railgun shot
Hit 10 enemies with a single railgun shot
Lure 10 zombies onto a single mine
Kill 7 enemies using a single air support powerup
Heal 300 points of damage using lifesteal in a single game
Kill a tunneler using a well-placed mine
Kill Sackhead using a chainsaw
Kill at least 30 enemies after your teammates die in a single round.
Do more damage than all of your teammates combined in a 3+ player game that lasts at least 4 rounds.
Defend the objective 500 times
Last 6 rounds without building any turrets or fences
Purchase all of the available upgrades in a single game
Get killed by the last basic zombie of the round.
Accumulate 500 explosion kills
Catch 500 enemies using the bear trap
Be within blood splatter range for 3000 dismembering kills
Kill Deadmass using the med gun
Complete the single player campaign.
Complete the single player campaign on normal without dying.
Complete the single player campaign on normal without taking damage.