It was designed to be different from Higurashi and Umineko, with a larger world compared to their isolated settings, and with the intent that the player can choose to just enjoy the story or optionally try to solve the mysteries themselves, a change influenced by the 1995 anime series Neon Genesis Evangelion.

The music is composed by returning When They Cry series staff, including Dai, Luck Ganriki, Xaki, and Uni Akiyama; and the opening theme is performed by Maria Sawada.

While at a convention outside Japan, Ryukishi07 asked recurring 07th Expansion composer Gin Kreuz how to localize the title in Japanese to make it sound more appealing.

This decision was influenced by the 1995 anime series Neon Genesis Evangelion, which both presents a straightforward narrative and hints at larger mysteries of its world.

To show gratitude to international fans of the series, he also specifically wrote the script to feature characters from around the world.

[2] The music tracks in the game were specifically composed to begin quickly, and give the listener a feeling for the song's mood within the first few seconds, as the developers wanted to avoid a situation where a scene ends before the player has gotten past a long prelude.

[14][2] In November 2020, Ryukishi07 announced that it had been delayed again due to the COVID-19 pandemic, which he considered too similar to the catastrophic events of the game for him to release Phase 2 at that time, describing it as a situation akin to if the monster Godzilla had attacked while the 1954 film was in production.

[19] Keiichi Yokoyama of Automaton was impressed with it, and said that its production values were noticeably improved compared to previous entries in the When They Cry series, he also described it as "for better or worse, a Ryukishi07 work".