Here is the full list of all 20 The Jackbox Party Pack 3 achievements. It takes around 6-8 hours to unlock all of the achievements on Windows.
Pick top three answers in final round
Guess the exact percentage
Catch the Faker on the first vote.
Vote against your own shirt in a battle
Get a Super Quiplash! (all player votes and 90% audience votes in a 5+ player game)
Win all your battles in Round 1, but lose all your battles in Round 2
Create a custom game
Write "gravy castle" and win a battle with it
Use all of your colors in a single drawing that then gets used on a shirt
Get all the votes in a single battle in a 5+ player game
Be the creator of every shirt in the final gauntlet
Faker gets through three tasks in a row without a single vote (or two tasks for three player games).
Play five games of Fakin' It in a row.
Play 40 You Gotta Point tasks.
Survive The Killing Floor 3 times in one game
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
Perfect guessing of higher/lower
Guess within 5% of an audience's answer