Here is the full list of all 20 The Jackbox Party Pack 3 achievements worth 1,000 gamerscore.
Created a custom game
Was the creator of every shirt in the final gauntlet
Got all the votes in a single battle in a 5+ player game
Voted against your own shirt in a battle
Survived The Killing Floor 3 times in one game
Picked top three answers in final round
Won all your battles in Round 1, but lose all your battles in Round 2
Answer 5 Trivia Questions in a row correctly
Play 3 games in a row with the same players
Get a score of 25 or more in the Math Killing Floor
Guess the exact percentage
Perfect guessing of higher/lower
Guess within 5% of an audience's answer
Get a Super Quiplash!
Write "gravy castle" and win a battle with it
Catch the Faker on the first vote.
Faker gets through three tasks in a row without a single vote.
Play five games of Fakin' It in a row.
Play 40 You Gotta Point tasks.
Use all of your colors in a single drawing that then gets used on a shirt