Here is the full list of all 31 Dark Zone Defense achievements.
Beat Elizabeth
Complete the tutorial
Kill 3000 monsters
Kill 20000 Monsters
Kill 100000 Monsters
Play the game 10 Times
Play the game 50 Times
Play the game 100 Times
Wound 1000 times
Aquire the maximum vision from ability
Has more than 2,000 stars at the time of death
Has more than 5,000 stars at the time of death
Use HP regeneration for 20 times
Receive 30 attacked from behind
Arrive At The 13th Level 3 Times
Complete 6 normal levels unharmed
Complete 10 normal levels unharmed
Complete all normal levels unharmed
Get the end level of Noraml Stage without using HP regeneration
Get the end level of Dark Stage without using HP regeneration
Stay with the first rifle and aquire the Silver Bullets
Successfully defend yourself 20 times with Iron Curtain
Beat Elizabeth In Dark Stage
Beat Mini
Beat Boss Mini In Dark Stage
Beat Wolfram
Beat Wolfram In Dark Stage
Beat Boss W.Y.L 30K
Beat Boss W.Y.L 30K In Dark Stage
Beat Chaos
Finish Huge Wave 3 times