Hallucigenia (ハルキゲニア)

Overview
Hallucigenia (ハルキゲニア) is a fangame by Trendy-Sabamiso (トレンディ鯖味噌) (Pixiv), one of the co-creators of Yume 2kki (ゆめ2っき). It stars two young girls named Aya (あや) and Aine (あいね). Its current version is 0.008.

Gameplay
You start out playing as Aya in a mostly barren room and access the dream world through a black book on Aya's bed, Aya then takes a different form in the dream world where you can explore.

Additionally, you also have an unlockable character called Aine,  unlocked as a playable character after completing the task. Aine's dream world has many of similarities with Aya's dream world, but in grayscale because of her colorblindness.

Unlike most of the fangames, the game doesn't have any background music, and has only 8 sound effects.

You can do some action in certain effects by long pressing Z button.

Plot
Aya enters her dream world from the black book on her bed. When in the dreamworld you are still Aya, but her appearance differs. It is possible Aya wishes to become this dream Aya.

Aine enters her dream world by sleeping on the bed. She lost her right arm, and she is also colorblind that she sees things in grayscale, either in reality or dream world.

Aya's Effects
Pressing the action button when Aya in normal form makes her body distort.

Aine's Effects
Pressing the action button when Aine in normal form makes her look at her lost right arm.

Original

 * Alternative Official Website
 * Developer's Website

Translations

 * Uboachan Thread