Yukiwo, a world prototype, showcases an unfinished state. The mention of "Imperfect graphics" indicates a work-in-progress version that did not reach a full release.  The nature of its gameplay and its original developer are unknown, highlighting its status as a pre-release artifact.  Its value rests in its historical significance as an example of an arcade game in development.

Yukiwo (World, prototype)

Youjyuden (Japan)