Here is the full list of all 50 South Park: The Stick of Truth achievements worth 1,000 gamerscore.
You have joined the KKK.
You farted on 10 enemies in the world that were knocked out.
You defeated 3 enemies in one battle while your buddy was knocked out.
You've unlocked all of the upgrades for a New Kid ability.
You defeated the Boss Hall Monitor while wearing freckles.
You collected 5 Chinpokomon.
Over the course of the game, you've scored 100 perfect attacks.
Over the course of the game, you've blocked 100 attacks.
You flung a turd of your own creation at an enemy.
Spend one day in South Park.
Defeat Kyle in battle.
Defeat Cartman in battle.
Befriend the Goths, just like everyone else playing this game.
Let Gingers bite you 3 times without blocking.
Summon Mr. Slave while in Mr. Slave's colon.
Find Jesus while playing as a Jew.
Open all garages in South Park.
Sell nothing the entire game.
Defeat Princess Kenny while looking like David Hasselhoff.
Fart on the Mayor, Father Maxi, Principal Vic, & Prime Minister.
Shit your pants during a boss battle.
Name yourself Douchebag.
Fart on a canine enemy while in Gnome form.
Hit 3 enemies with a single fart outside of combat.
Defeat Princess Kenny while in your Makeover disguise.
Fart on each available buddy in the game.
Interrupt 5 channel attacks with a fart.
Defeat the Meth Tweekers while wearing the Evil Cartman goatee and the bald cap.
Defeat Kenny while sick with Dire AIDS.
Watch your parents have sex for 60 seconds.
Successfully block every enemy attack in a single, non-tutorial battle.
Complete the game without ever ending a combat with a buddy knocked out.
Collect 15 Chinpokomon.
Collect all the Chinpokomon.
Befriend your Dad.
Befriend Half of South Park.
Befriend all of South Park.
Sell 300 junk items.
Defeat Princess Kenny and Recover the Stick of Truth.
Kill 20 enemies with Cartman's ass.
Fart on people 100 times
Fart on animals 25 times.
Shit Your Pants in battle three times.
Complete half of the available costume sets.
Complete all available Costume Sets.
Fart on the corpse of an aborted Nazi Zombie fetus.
Befriend Crab People and Underpants Gnomes.
Have Kenny Die 10 times in battle over the course of the game.
Spend $500.
Collect all the weapons and costumes available in the game.