Conexus

Overview
Conexus is an English Yume Nikki fangame created by SkelWT in RPG Maker 2003. It follows an unnamed traveler as they search around a strange realm in order to learn why they were summoned there.

Gameplay
Conexus is a calm and atmospheric Yume Nikki fangame that follows the traditional formula, although does not contain any effects. The game doesn't feature a Nexus either, as instead all of the locations are fully interconnected, removing the need to return to any sort of starting point. There are save points beside nearly every connection, allowing the player to save their progress and resume playing from any location that they choose.

Throughout the world, there are three specific NPCs who you must find and speak to in sequence in order to access the ending. Talking to them in the right order results in you receiving a Music Box which contains an important tune. Playing the tune on an instrument found within a certain location allows you to access a hidden area that leads to the end of the game.

Both of the endings have the same requirements to be accessed, either of them being picked from a single selection prompt contained within the ending cutscene.

Plot
You play as an unnamed traveler who wakes up in an alien realm of interconnected worlds known as the Conexus. A mysterious trio guides you on the path to figuring out who or what brought you there in the first place, speaking of a Prophecy that you supposedly play a large part in.

You learn the story of Rubira, the creator and former ruler of the Conexus who was disgraced by her own people and banished away using magic. The people eventually began to lose their ambition after forsaking their only leader, causing the whole realm to become quiet and gloomy. According to the Prophecy, you were summoned to the Conexus in order to return the realm to its former glory.

It isn't until you reach the ending that you find out the Prophecy was a cover to keep the real narrative hidden from you. You find out that Rubira is being kept trapped away from the Conexus by a magical artifact called the Red Seal, which requires the power of four people in order to be destroyed. The mysterious trio, who reveal themselves to be Rubira's last remaining followers, want to break the Red Seal so that she can return to her former position as their leader. Since they know nobody else in the Conexus would ever help them with it, they resorted to summoning you, an unbiased party from a planet outside of their realm, in order to act as the fourth person instead.

Out of courtesy, they ultimately leave the choice up to you. You can either help them destroy the Red Seal in order to free Rubira and return her to power, or you can turn down their proposition and get sent back home instead.