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