Here is the full list of all 51 Instant Dungeon! achievements.
Kill monsters with both sides of one fireball spell
Kill 3 monsters with 1 axe
Stab 10 monsters in the back with a knife
Throw 50 knives
Kill 50 monsters
Reach Round 10 in Practice Formula
Kill 25 Skeletons
Sneak past the Pumpkin Master in Action Recipe
Dodge the Dracolich in Action Recipe
Kill 2 monsters with 1 axe
Throw a weapon at a boss
Escape from the Red Dragon in Action Recipe
Kill a monster
Pick up a treasure
Pick up 1000 treasures
Pick up 10,000 treasures
Pick up 100 diamonds
Die 50 times
Kill 500 monsters
Kill 100 Skeletons
Kill 25 Cyclops
Kill 100 Cyclops
Kill 25 Wraiths
Kill 100 Wraiths
Throw 10 weapons at boss monsters
Kill a Pumpkin Demon with a pumpkin bomb
Kill 3 monsters with one lightning spell
Kill a monster with a frozen monster
Kill 2 monsters with one frozen monster
Axe 10 monsters in the back
Kill 25 monsters with pumpkin bombs
Freeze 25 monsters
Cast 50 fireball spells
Light 50 torches
Use 50 light spells
Use 50 crystal balls
Use 50 time freeze spells
Break 50 shields
Break 50 helemts
Exit the lair of the Blue Dragon in Action Recipe
Escape the Stone Giants in Action Recipe
Survive the Wizard in Action Recipe
Reach Level 50 in any game flavor
Reach Level 30 in Weak Sauce
Complete 50 quests in Adventure Mix
Rescue 25 friends in Rescue Relish
Reach Level 15 in Dark Roast
Reach Level 10 in Soul Succor
Reach Level 12 in Boss Blend
Reach Level 24 in Boss Blend
Survive to Round 15 in Maxima Mash