The First 15 Minutes of Divi-Dead (Dreamcast, 18+)

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The story of Divi-Dead encompasses the horror and Hentai genres, and is designed for adults only. You are trying to find out why so many strange things have been going on in your school. Largely, this involves moving around the school and encountering sights and characters who can give you a clue. The game has multiple endings depending on your choices. There is a full MIDI soundtrack, and hand-painted backgrounds.