Here is the full list of all 20 Donut County achievements. It takes around 2-3 hours to unlock all of the achievements on Windows.
Set Pepper's trailer on fire.
Make Chef's secret soup recipe.
Find Trash King's secret getaway vehicle.
Break 3 dozen eggs.
Complete the Trashopedia.
Fly through the donut hole.
Bring everyone back from underground.
Win the boss fight.
Destroy Trash King's monument.
Complete the boss fight without taking damage.
Lose the boss fight.
Destroy Trash King's monitor.
Break into the vault at Raccoon HQ.
Hack into the mainframe.
Quack 100 times.
Destroy Raccoon Lagoon.
Destroy the donut shop.
Stock up on gamer fuel.
Finish Gecko Park without collecting the radio.
Release the hot air balloon.