Costume Quest is an adventure role-playing video game developed by Double Fine Productions and published by THQ. In the game, the player controls a child that is trick-or-treating with their twin on Halloween night when they encounter a monster that kidnaps the sibling. The player must travel around the local neighborhood collecting items for their costume, candy and fellow children as companions in order to face the monster and rescue the sibling. The costume aspects are used in battle segments, where the player character and companions are transformed into the monsters and creatures they are dressed as to fight other monsters. The game is a downloadable title and was released on October 20, 2010 on the Xbox Live Arcade and PlayStation Network services. A port to Microsoft Windows through the Steam platform was released about a year later.