Here is the full list of all 35 Postal III achievements.
Kill 1000 unarmed bystanders.
Complete game using only melee.
Arrest eco zealots leader.
Finish your business with Krotchy.
Take out all the criminal scum infesting Catharsis!
Kill/incapacitate 235 terrorists.
300 headshot/decap kills.
Escape from prison.
Respawn 20 times.
Smash 50 windows.
100 kills using machete in melee.
50 badgersaw kills.
50 kills using cat.
200 kills using M-60.
50 kills using boomerang machete.
Spend 900 seconds or more in catnip bullet time.
50 kills using bees.
Euthanise 30 elderly folks.
150 kills using fire.
Piss 100 gallons of urine.
Destroy 50 cars.
Beat game with zero kills.n(zombies and bosses don't count)
Kill no animals in one playthrough.
Complete game using only the pistol.
Complete Good path without falling off.
Complete game killing only males.
Make Venezuela peacemakers go home.
Beat the game once. No restrictions apply. Everyone's a winner.
Taze 200 victims.
Arrest 200 perps.
Injure yourself.
Return Thegways to the owner
Suck up 500 items with the shop vac.
Choose path for the first time.
Disobey orders, given to you, and see what happens.