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