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