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