Here is the full list of all 10 Who is the Liar? achievements.
In the Minigame, find and deliver all gifts without making a mistake within 2 minutes.
Find and deliver all gifts in the Minigame.
Find the liar at the Merry Christmilly party.
Pop 25 balloons in the Minigame.
Win the Minigame against the characters of the Madmily mansion.
Find the liar at Magnolia's party.
Find the liar at the Madlloween party.
Find out who is hiding in the Minigame.
In the Minigame, find the mysterious character.
Finish the game and... !!?