Here is the full list of all 19 Ben and Ed achievements.
Impress 200 viewers.
Kill 50 chicken.
Kill 20 chicken.
Finish the game.
Reunite with your friend.
Beat 12 level unharmed.
Beat Hans.
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.
Collect 100% of all candymeat.
Beat all level unharmed.
Kill 100 chicken.
Impress 700 viewers.
Impress 1100 viewers.