Here is the full list of all 25 Epic Party Quest achievements.
Completed your first mini-game.
You had at least one friend.
You had at least two friends.
You had at least three friends.
Unlocked the unlockeable.
Everybody won, so nobody won.
You wanted more and got it.
You lost control over the story.
You saw things from different perspective.
All players choose classic outfits.
All players choose some of the colours.
The dish was served cold.
Reached the top of the mountain.
At least you tried.
...and it was not even your final form.
You got it all right.
You were not an idiot sandwich.
You were the last man standing.
Hand-eye coordination was top notch.
You kept your cool in the face of the lasers.
You see everything and hear nothing.
You achieved last-minute victory.
…but at least no one was hurt in a process.
You got yourself a fine collection.
You completed the final quest.