Twins Reynold and Wren are trick-or-treating in their new neighbourhood when one of them gets kidnapped by a monster with a sweet tooth. Making friends and taking on strange monsters, it is up to Reynold and Wren to save their Halloween!

Costume Quest is a light-hearted Halloween-themed JRPG in which players find and use interchangeable costumes imbued with superpowers that can be used to fight monsters attempting to steal all the Halloween candy and disrupt trick-or-treating.