Here is the full list of all 31 Wayward Souls achievements.
Bought a Gift upgrade.
Bought six Gift upgrades.
Defeated a boss in under 20 seconds.
Power attacked an enemy right after inflicting a normal attack.
Died to the same boss as 4 different characters.
Went down a floor while at critical health.
As the Warrior, took out your shield a second before being struck.
As the Warrior, defeated a strong enemy using only throwing axes.
Defeated the gold boss as the Warrior.
As the Adventurer, defeated 5 enemies in a row using only your lantern.
As the Adventurer, stunned a strong enemy 4 times in the same fight.
Defeated the gold boss as the Adventurer.
As the Mage, nullified an enemy magic projectile using the Gust ability with the starter robe.
As the Mage, used 4 different targeted attack scrolls in 4 seconds on an enemy.
Defeated the gold boss as the Mage.
As the Rogue, defeated 5 enemies in a row using only dashes and backstabs.
As the Rogue, used your starter boots to stun 3 enemies with a single kick.
Defeated the gold boss as the Rogue.
As the Spellsword, struck 7 different enemies with a single power attack charge.
As the Spellsword, used a scroll to nullify 3 enemy spells at the same time.
Defeated the gold boss as the Spellsword.
As the Cultist, defeated an enemy with a stab and point-blank dagger throw in a row, twice.
As the Cultist, blinded 5 enemies at a time, then defeated them all without taking damage.
Defeated the gold boss as the Cultist.
Collected 200 hats.
Cleared the Labyrinth on one character.
For one character: acquired all upgrades, cleared every dungeon up through Labyrinth, and got their three class-specific achievements.
Reached the 100th floor of the Eternal Shadow.
Cleared the Labyrinth as all six Wayward Souls.
Conquered the Gauntlet.
Triumphed in the Arena.