Here is the full list of all 10 Who is the Liar? achievements.
Finish the game and... !!?
Find out who is hiding in the Minigame.
In the Minigame, find the mysterious character.
Find the liar at the Madlloween party.
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.
Win the Minigame against the characters of the Madmily mansion.
Pop 25 balloons in the Minigame.
Find the liar at Magnolia's party.