Here is the full list of all 51 EARTH DEFENSE FORCE 4.1 The Shadow of New Despair achievements.
Defeated 4000 flying-type bugs.
Destroyed 900 Hectors.
Healed another player in co-op play.
Obtained 50% of all available weapons.
Defeated 120 shield bearers.
Defeated 24 death queens.
Defeated 12,000 spider-type bugs.
Destroyed 6 motherships.
Defeated 24 queens.
Rescued 5 other players in co-op play.
Destroyed 200 underground tunnel exits.
Defeated 2400 Dragons.
Cleared all stages on Normal difficulty as a Wing Diver.
Defeated 20,000 ant-type bugs.
Wing Diver's health has reached 550.
Cleared all stages on Normal difficulty as a Ranger.
Defeated 200 Deroys.
Reached a height of 200 meters.
Ranger's health has reached 1000.
Obtained 10% of all available weapons.
Cleared all stages on Hard difficulty as a Ranger.
Cleared all stages on Hardest difficulty as a Ranger.
Cleared all stages on Inferno difficulty as a Ranger.
Cleared all stages on Hard difficulty as a Wing Diver.
Cleared all stages on Hardest difficulty as a Wing Diver.
Cleared all stages on Inferno difficulty as a Wing Diver.
Cleared all stages on Normal difficulty as an Air Raider.
Cleared all stages on Hard difficulty as an Air Raider.
Cleared all stages on Hardest difficulty as an Air Raider.
Cleared all stages on Inferno difficulty as an Air Raider.
Cleared all stages on Normal difficulty as a Fencer.
Cleared all stages on Hard difficulty as a Fencer.
Cleared all stages on Hardest difficulty as a Fencer.
Cleared all stages on Inferno difficulty as a Fencer.
Obtained all available weapons.
Destroyed 5000 flying drones.
Destroyed 500 carriers.
Destroyed 12 quadruped fortresses.
Defeated 40 king spiders.
Destroyed 150 red drones.
Defeated 360 Retiarii.
Destroyed 6 flying-type bug nests.
Destroyed 2000 flying vehicles.
Destroyed 200 large transport ships.
Defeated 20 Greater Wild Dragons.
Destroyed 20 Argos.
Destroyed 30 Erginuses.
Destroyed 6 Brains.
Air Raider's health has reached 1000.
Fencer's health has reached 1250.
Rescued 50 other players in co-op play.