The Abyssal Depths Add-on for One Deck Dungeon has 11 achievements.
Win a game with the Aquamancer in your party.
Win a game with the Dragoon in your party.
Win a game with each Fiend from Abyssal Depths.
Win a game with each Fiend from Abyssal Depths on the Difficult side.
Reduce a Fiend to Threat Level 0.
Reduce a Fiend to Threat Level 0 three times in a single game.
Win a game without ever confronting the Fiend.
Win a game in the Smoldering Ruins with a Fiend.