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