Here is the full list of all 19 Ben and Ed achievements.
Impress 1100 viewers.
Impress 700 viewers.
Beat all level unharmed.
Collect 100% of all candymeat.
Kill 100 chicken.
Kill 50 chicken.
Finish the game.
Reunite with your friend.
Beat Hans.
Beat Hans' second masterpiece.
Beat 12 level unharmed.
Collect 50% of all candymeat.
Impress 200 viewers.
Kill 20 chicken.
Collect 20% of all candymeat.
Beat 5 level unharmed.
Beat Hans' first masterpiece.
Reach a checkpoint in one piece.
Finish the tutorial.