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