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.
Destroy Trash King's monitor.
Break into the vault at Raccoon HQ.
Make Chef's secret soup recipe.
Finish Gecko Park without collecting the radio.
Break 3 dozen eggs.
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.
Hack into the mainframe.
Quack 100 times.
Destroy Raccoon Lagoon.
Destroy the donut shop.
Stock up on gamer fuel.
Set Pepper's trailer on fire.
Release the hot air balloon.