Here is the full list of all 24 Long Drop achievements.
Fling first poop after 60 seconds
Bounce poop off surfaces 100 times
Fling 3 poople under 1 second
Fling a poople at max speed
Unlock Mr. Brown
Unlock Slipper
Unlock Sir Sticks-A-Lot
Unlock Behemoth
Unlock Nutjob
Reach the top of the leaderboard
Unlock all outfits
Fling 50 poople
Fling 100 poople
Fling 200 poople
Fling 500 poople
Unlock 5 outfits
Unlock 10 outfits
Unlock 20 outfits
Swap between poople 10 times during a level
Beat 35 levels
Beat 70 levels
Pop 20 vermin
Use the power of adhesion 20 times
Break 30 planks