Here is the full list of all 23 Ben and Ed - there are Blood Party achievements.
Hold on to chickens for 30 minutes.
Hold on to chickens for 10 minutes.
Produce 1000 meatblocks.
Produce 100 meatblocks.
Cut off 1000 parts of your enemies.
Cut off 100 parts of your enemies.
Inject acid into 20 enemies.
Meet Ben.
Find Hans.
Place 50 Trashcans.
Create Ed
Beat all singleplayer maps.
Build your own map.
Cut off 10 parts of your enemies.
Produce 10 meatblocks.
Survive 60 minutes as head.
Hold on to chickens for 1 minute.
Survive 10 minutes as head.
Never give up!
Survive one minute as head.
Finish the tutorial.
Finish a race headless.