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