Here is the full list of all 31 Gene Rain achievements.
200 kills in Defensive warfare.
Accumulated player deaths 25 times.
Unlock 4 specialist weapons.
Death by driving a mecha.
Destroy 50 machine soldiers with melee attacks.
Hit 3 times by any large mecha.
Accumulatively destroyed 6 UFO fighter.
Destroy 4 machine soldiers at once with a grenade detonation.
Drive mecha, trample to kill 30 enemies
Defensive warfare adhere to 5 waves of enemy attacks.
Complete the Campaign on any difficulty.
Defeat the final BOSS-BERSERKER
Completely upgrade one weapon.
Salman's Shield takes 2500 damage.
Destroy 1 UFO fighter with a grenade detonation.
Defeated 10 Death Claw or Observer.
Destroy 100 wreckage of the machine soldiers.
Defeated 3 Shadowblade.
Die 10 times.
Total number of Cores reached 75.
Li Ying used skills 3 times.
Destroyed a Mechanical Destroyer.
Die 5 times.
First use of equiproom.
Destroyed a UFO fighter.
Defeated 20 Battlefield or Mechanical mosquito.
Defeated 30 Mutant.
Defeated 30 armored guard's.(Black\Silver\Guardian)
Use specialist weapons for the first time.
Blasting 10 barrels.
Alex's first use of skills.