FallDown is the first part of MAMIYA's story, available to read for free as a demo. It was first released in Japanese on December 29th, 2016, and later released in English on April 30th, 2021. An updated demo was released on September 21st, 2023 at Tokyo Games Show, ahead of Doomsday Dreams's release. There are several notable changes, both narratively and mechanically, between the Legacy Version of FallDown and the final version released for the Complete Collection.
FallDown: Intro
FallDown: Kikuchi Ryou
FallDown: Toujou Minato
FallDown: Morichika Haruki
FallDown: Suou Keito
FallDown: Outro
