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