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.
Lose the boss fight.
Complete the boss fight without taking damage.
Set Pepper's trailer on fire.
Complete the Trashopedia.
Find Trash King's secret getaway vehicle.
Fly through the donut hole.
Bring everyone back from underground.
Win the boss fight.
Destroy Trash King's monument.
Destroy Trash King's monitor.
Break into the vault at Raccoon HQ.
Hack into the mainframe.
Destroy Raccoon Lagoon.
Destroy the donut shop.
Make Chef's secret soup recipe.
Break 3 dozen eggs.
Stock up on gamer fuel.
Finish Gecko Park without collecting the radio.
Quack 100 times.
Release the hot air balloon.