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