Here is the full list of all 27 Super Dungeon Bros achievements.
Complete all missions
Kill 5,000 wasps
Kill 7,500 bunnies
Kill 10,000 bonies
Kill five enemies with a pot
Play the game with every weapon
Play the game with every hammer
Complete a dungeon with each kind of weapon
Play the game with every wand
Play the game with every sword
You played the game with every crossbow
Complete a dungeon without dying
Have the top score in a 4 player online game
Defeat Duke Spookem
Complete 10 missions
Complete all of a day's missions in one run
Play the game wearing any helmet
Defeat Frost Queen
Complete a dungeon with everyone having the same type of weapon
Defeat Cult Overlord
Kill an enemy with another bro
Beat a level before you reach threat level 3
Reach Duke Spookem for the first time with any weapon
Complete one mission
Throw all bros over a ledge in one game
Stay alive in threat level 5 for 30 sec
Be the only bro alive when everyone else died