Here is the full list of all 35 Postal III achievements.
Kill/incapacitate 235 terrorists.
Euthanise 30 elderly folks.
50 kills using bees.
Spend 900 seconds or more in catnip bullet time.
Kill 1000 unarmed bystanders.
Arrest 200 perps.
50 badgersaw kills.
150 kills using fire.
Taze 200 victims.
Respawn 20 times.
Make Venezuela peacemakers go home.
300 headshot/decap kills.
Take out all the criminal scum infesting Catharsis!
Arrest eco zealots leader.
Finish your business with Krotchy.
50 kills using cat.
100 kills using machete in melee.
50 kills using boomerang machete.
Destroy 50 cars.
Suck up 500 items with the shop vac.
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.
Escape from prison.
Beat the game once. No restrictions apply. Everyone's a winner.
Smash 50 windows.
Piss 100 gallons of urine.
Return Thegways to the owner
200 kills using M-60.
Choose path for the first time.
Disobey orders, given to you, and see what happens.
Injure yourself.