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