Here is the full list of all 50 South Park: The Stick of Truth achievements worth 1,000 gamerscore.
While inside Mr. Slave, you summoned Mr. Slave.
In three separate battles, you've taken a shit in your pants.
You befriended both crab people and gnomes.
You have collected half of the available costume sets.
You've spent $500.
You sold 300 junk items.
You've farted on a dog while in gnome form.
You've farted on every buddy in the game.
You've farted on animals 25 times.
You've let Kenny die in combat 10 times over the course of the game.
You opened all of the garages in South Park.
You defeated Princess Kenny and recovered the Stick of Truth.
You completed the game without selling any items.
You defeated Princess Kenny in your girl makeover disguise.
You defeated Princess Kenny while living with Dire AIDS.
You farted on four major authority figures.
You made friends with half of South Park.
You befriended your father.
You defeated 20 enemies using Cartman's Ass.
You collected 15 Chinpokomon.
You farted on the corpse of an aborted Nazi Zombie fetus.
You successfully blocked every enemy attack in a single (non-tutorial) battle.
You watched your parents have sex for 60 seconds.
You farted on 10 enemies in the world that were knocked out.
You defeated the High Jew Elf Kyle in battle.
You defeated 3 enemies in one battle while your buddy was knocked out.
Gingers have bitten you 3 times without you blocking.
You befriended the Goths, like everyone else playing this game.
You've farted on people 100 times.
You've unlocked all of the upgrades for a New Kid ability.
You completed your first day in South Park.
You collected 5 Chinpokomon.
You have joined the KKK.
You knocked out 3 or more enemies with a single fart outside of battle.
Over the course of the game, you've scored 100 perfect attacks.
You shat your pants during a boss battle.
Over the course of the game, you've blocked 100 attacks.
You defeated the Boss Hall Monitor while wearing freckles.
You flung a turd of your own creation at an enemy.
You accepted your fate and chose the name Douchebag yourself.
Defeat Cartman in battle.
Find Jesus while playing as a Jew.
Defeat Princess Kenny while looking like David Hasselhoff.
Interrupt 5 channel attacks with a fart.
Defeat the Meth Tweekers while wearing the Evil Cartman goatee and the bald cap.
Complete the game without ever ending a combat with a buddy knocked out.
Collect all the Chinpokomon.
Befriend all of South Park.
Complete all available Costume Sets.
Collect all the weapons and costumes available in the game.