Nightmare Castle

Overview
Nightmare Castle is a physical re-imagining loosely based upon Amiha's Nightmare Castle (悪夢城のアミハ), both of which were created by Noyemi K. Boasting a color scheme of only 8 colors with a variety of different dreamscapes for the player to explore as well as a collectable currency that can be traded to the shopkeeper in exchange for effects that change the player model.

Gameplay
The gameplay of Nightmare Castle is similar to most Yume Nikki games, taking place in a dream world with the ability to wake up at anytime where the player must explore various differing places and collect effects that change Ruho's model and give her extra abilities.

Scattered across the worlds are treasures, a collectable currency that can be traded to the exploring shopkeeper Masha in order to gain effects. Nightmare Castle also features an element of randomness to it, upon entering a doorway, players will sometimes be teleported to a different part of the dream world.