Here is the full list of all 21 Deep Dark Dungeon achievements.
Collect 30 medals.
Finish the game without continuing.
Finish the game alone.
Defeat the Giant Lava Worm.
Defeat the Goblin Squad.
Buy first medal.
Defeat the Lichen Lich.
Finish the game with 2 players.
Finish the game with more than 3 players.
Finish the game without medals.
Finish a level collecting less than 10 golds.
Finish the game with single weapon.
Destroy a enemy with 20 different weapons.
Be killed in tutorial.
Fry 200 Eggs in dungeon.
Be killed by Lichen Lich.
Make a minion kill the Lichen Lich.
Defeat Ninja Goblin with a katana.
Defeat Great Lava Worm with a book.
Defeat King of Chess with a musket.
Have 3000 golds by the end of game.