Here is the full list of all 50 ELEX achievements. It takes around 80-100 hours to unlock all of the achievements on Windows.
Learned all Berserker skills.
Learned all Outlaw skills.
Cold value has reached 90
Served the Hybrid.
Picked 100 locks.
Cracked 50 safes
Learned all dexterity skills.
Collected 20 pictures.
Killed 1000 monsters.
Modified weapons 20 times
50 successful pickpockets
Learned all fighting skills.
Learned all Cleric skills.
Learned all character skills.
Learned all survival skills.
Fed Mana to the Hybrid.
Completed ELEX.
Sided against the Hybrid.
Completed - Showdown with Kallax.
Completed - Old Obligations.
Started a relationship.
Completed - Zardom's Battle Plan.
Earned 100,000 Elex shards.
Cold is 10 or lower.
Found Calaan
Fallen to death 20 times.
Completed - Chaos of Emotions.E86
Joined the Outlaws.
Joined the Berserkers.
Joined the Clerics.
Killed 20 Albs.
Completed - Tramp Confederacy.
Reached level 20.
Completed 300 missions.
Killed 300 monsters.
Completed - Origin The Power of the Center.
Killed 50 people
Killed 20 bandits.
Completed - Decaying Powers.
Sealed the fate of Abessa City.
Completed - The Claws.
Teleported 20 times
Earned 10,000 Elex shards.
Completed - Stolen Equipment.
5 companions
Killed 20 monsters.
Earned 1000 Elex shards.
Played 80 hours of Elex.
Completed - Survival
First jet pack flight