Here is the full list of all 35 Donuts'n'Justice achievements. It takes around 3-4 hours to unlock all of the achievements on Windows.
Kill Your First Enemy
Eat 100 Donuts
Die 50 times
Kill 100 civilians
Kill 1.000 Enemies
Kill 50 Enemies with Sniper Rifle
Make 500x Combo
Kill 100 Enemies with FlameThrower
Kill 100 Enemies with Freeze Gun
Gather 1.000 Dollars
Kill All the Bosses
Collect 1000 Badges
Save 100 civilians
Earn Score Higher than 500
Earn Score Higher than 1000
Earn Score Higher than 1500
Earn Score Higher than 2000
Earn Score Higher than 2500
Earn Score Higher than 3000
Earn Score Higher than 4000
Earn Score Higher than 5000
Throw 100 grenades
Finish the game on the ThumbSucker difficulty
Wear the Santa Hat
Eat 100 Mushrooms
Change the DNA of enemies 100x
Wear the Viking Helmet
Wear the Sombrero
Wear the King Crown
Wear the Chef Hat
Wear the Pope Hat
Collect 100 Pumpkins
Collect 100 Candies
Summon 77 Witches
Catch 69 Ghosts