Here is the full list of all 25 Quest of Dungeons achievements.
Defeat 3 ghosts of a past Hero
Beat a Custom game in Hard or above with 10 floors
Beat Rackan Mansion
Beat Game with NecroDancer
Disarm a trap and get loot!
Defeat 20 Bosses
Complete 50 quests
Beat Game in Hell
Find 50 hidden stash
Beat Game in Hard
Beat Game with Wizard
You listened until the end
Beat Game in Normal
Beat Game with Shaman
Pick 1M Gold
Beat Game with Warrior
Beat Game in 30m
Beat Game in Easy
Beat Game with Assassin
Buy all stock
Beat a Boss
Complete a quest
Unlock a door
Unlock Chest
Beat the Rothar Mansion