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