Demon City X: Nightmare under the Moon is an action role-playing game developed by KCET(PS version) and KCEN(SS version) and released by Konami. Demon City X: Nightmare under the Moon is available on the PS platform of 1997, and the transplanted version is available on the Sega SS platform of 1998. In 2007, KONAMI launched a downloaded version of XBOXLIVE on Microsoft XBOX360.
Demon City X: Nightmare under the Moon is recognized as the most successful work in the series of Demon City. "Silly Music under the Moon" changed the pure action style of previous works, added a lot of RPG elements and map exploration elements, supplemented by wonderful plots, exquisite pictures and beautiful music, so it was widely praised.