Here is the full list of all 39 Erra: Exordium achievements.
Find your first gun. You will need guns...lots of guns
Dive into your memory. Reclaim your past
Eliminate 3 Enemy Units by using a mine detonation. Precise shot is all what you need
It will help you to gain experience. Painful but still useful experience
Eliminate three hostiles by detonating the red fuel barrel. Mechatrons are known to go up in flames spectacularly
Eliminate 10 drones using only cold weapons. Show them your skill
Block 20 enemy attacks with perfect timing. Do what must be done
Kill your 10 enemies by using a hand grenade. Don't rush, if you don't want to die
Find and open 10 secret message capsules to reveal hidden treasures and important notes
Defeat the Imgud
Don’t miss posters, just witness the greatness
Destroy 50 Mechatrons
Inflict 100 gunshot wounds on Mechatrons
Kill 25 Mechatrons with cold weapon
Kill 25 Mechatrons with guns
Shoot the chain on the chandelier and kill the Mechatron with it
Shoot down 15 mines
Block 50 enemies attack
Block 30 enemy melee attacks
Use and Stan 15 enemies by EMI
Brake 5 lamps
Break 30 doors
Collect 500 rounds
Destroy 5 enemy missiles with firearms
Destroy 69 soda cans
Spot a star in the telescope
Find an artifact that increases attack speed
Find an artifact that extends enemies stun time
Find an artifact that speeds up firearm reload
With backpack, you can carry an extra 10 rounds
Your health now regenerates
Melt the protective shield of the alien object with lasers
Finish your Adventure