A game where the central plot element is some kind of mystery, generally either a murder or a missing person.
Ballade for Maria
Blind Games
Deja Vu: A Nightmare Comes True
Electronic Device Marian
Etsuraku No Gakuen
Eve Burst Error
Gakuen Bakuretsu Tenkousai
Jack: Haitoku no Megami
St Jeremiah Gakuen