Here is the full list of all 31 Barbearian achievements.
Compeleted all special quests
Defeat Moo Mobile
Complete all Master Classes
Unlock all weapon pickups
Rescue all trapped minions
Completed all quests at Strange Machinations
Collect a total of 250k loot
Defeat the rhyme blaster, the only true lyrical master
Defeat Ancient Mechanism
Completed all quests at Valley of Bones
Take down 50k enemies
First memory unlocked
Fire a weapon pickup 1k times
First Master Class completed
Defeat The Absorber
Completed all quests at Corrupted Forest
Walk 10k
Defeat Megaskull
Completed all quests at Skeletal Park
Reach maximum chain (999)
Collect a total of 25k loot
Swing your axe 1k times
Reach 500 chain
Complete the first quest
Free your first minion
All memories unlocked
Wasted perfectly good loot on some boxes
Defeat Master Arbitrator
Defeat Meta Engine
Complete the game
Complete the game with 100% completion rating