A hidden object game, also called hidden picture or hidden object puzzle adventure (HOPA), is a subgenre of puzzle video games in which the player must find items from a list that are hidden within a scene. Hidden object games are a popular trend in casual gaming.[1][2] Time-limited trial versions of these games are usually available for download, although many are free to download on app stores. They primarily make money through in-app purchases and ads. Popular themes include detective crime stories, adventure, gothic romance, and mystery.[3]
Mystery titles, particularly hidden-object games, have become a hugely popular segment of the casual-game market.