Here is the full list of all 50 South Park: The Stick of Truth achievements worth 1,000 gamerscore.
You've collected all of the available costumes
You own all the weapons and costumes available in the game
You defeated Princess Kenny while living with Dire AIDS
While inside Mr. Slave, you summoned Mr. Slave
You farted on the corpse of an aborted Nazi Zombie fetus
You've let Kenny die in combat 10 times over the course of the game
You found Jesus while playing as a Jew
You defeated 3 enemies in one battle while your buddy was knocked out.
You've spent $500
Everyone in South Park is your friend
You sold 300 junk items
You've farted on a dog while in gnome form
You defeated Princess Kenny and recovered the Stick of Truth
You completed the game and never ended a battle with your buddy knocked out
You completed the game without selling any items
You defeated Princess Kenny while looking like David Hasselhoff
You defeated Princess Kenny in your girl makeover disguise
You have collected half of the available costume sets
You collected all of the Chinpokomon
You befriended both crab people and gnomes
You defeated 20 enemies using Cartman's Ass
You've farted on every buddy in the game
You farted on four major authority figures
Over the course of the game, you've scored 100 perfect attacks
You interrupted 5 channel attacks by using a fart
You watched your parents have sex for 60 seconds
You defeated the Grand Wizard Cartman in battle
You defeated the High Jew Elf Kyle in battle
Gingers have bitten you 3 times without you blocking
You knocked out 3 or more enemies with a single fart outside of battle
You befriended the Goths, like everyone else playing this game
You befriended your father
You made friends with half of South Park
You opened all of the garages in South Park
You collected 15 Chinpokomon
Over the course of the game, you've blocked 100 attacks
You completed your first day in South Park
You have joined the KKK
In three separate battles, you've taken a shit in your pants
You shat your pants during a boss battle
You've unlocked all of the upgrades for a New Kid ability
You defeated the Boss Hall Monitor while wearing freckles
You've farted on people 100 times.
You farted on 10 enemies in the world that were knocked out
You flung a turd of your own creation at an enemy
You've farted on animals 25 times
You successfully blocked every enemy attack in a single (non-tutorial) battle
You defeated the Meth Tweekers while wearing the Evil Cartman goatee and bald cap
You collected 5 Chinpokomon
You accepted your fate and chose the name Douchebag yourself