Full list of all 15 One More Dungeon achievements worth 1,000 gamerscore. It takes around 15-20 hours to unlock all of the achievements on Xbox One.
Complete the first level
Complete five levels
Complete eight levels
Complete the game
Start the game with any mutator
Buy all the mutators
Complete a level with "Fog" or "Broken cartridge" mutator
Complete a level with "No margin for error" or "Curse" mutator
Squash 25 bugs
Finish the level in under 3 minutes
Die after drinking the poison
Kill the Ancient Necromancer
Kill the Elder Flower
Spend 50 coins
Put the items in all the inventory slots