Here is the full list of all 15 Barbarian Brawl achievements.
Block enemy attacks
Die more
Kill enemies with knife
Brynhildr kills
Mr. Rotten kills
Do damage to enemies
Take damage from enemies
Kill enemies with axe
Kill enemies with club
Kill enemies with halberd
Make some killing sprees
Kill enemies with scythe
Stun enemies
Get survivor mark
Kill enemies with sword