Crimsooon Sun Release Date Announced: July 17

I'm happy to announce that Crimsooon Sun has successfully passed Steam review and will be released on Friday, July 17.

I'd like to take this opportunity to introduce the game.

Overview

Crimsooon Sun is the PC version of a detective novel adventure originally released for iOS and Android (Japanese only) at the end of December 2024.

The story was inspired by a real report of Dual Suns phenomenon that I encountered at an academic conference. Although it is a mystery game, it is not a murder mystery, and it contains no graphic or grotesque content.

For the PC release, the interface has been redesigned for keyboard, mouse, and controller play. The game also includes a full English translation, improved presentation, additional illustrations, and new loading animations.

Other than these improvements, however, the story and gameplay remain essentially unchanged from the original release.

Genre and Gameplay

As described on the store page, Crimson Sun is a DETECTIVE NOVEL ADVENTURE.

What does that mean?

Simply put, the game has no story choices outside of deduction, no minigames, no game overs, and no multiple endings. It is designed to be experienced as a novel.

The basic gameplay is similar to a traditional visual novel without branching choices. However, it features a unique information-gathering mechanic called the Trigger System.

The Trigger System was inspired by the one used in Mikagura Shoujo Tanteidan (Mikagura-Girls-Detective). Once during each section of the story, you may pull a Trigger to obtain a "bullet," which also unlocks a new Trigger Note containing additional information.

There is, however, one major difference between the two games.

In Mikagura Shoujo Tanteidan, pulling the correct Trigger awards points. You must earn enough points before you can proceed to the deduction phase, meaning the game immediately tells you whether your choice was correct.

Crimsooon Sun works differently.

When you pull a Trigger, you simply receive new information. At that moment, there is no concept of a "correct" or "incorrect" Trigger.

Each Trigger Note contains four hidden tags. Some tags become visible after collecting three notes with the same tag, while others are revealed through special cut-in events triggered by specific combinations of information. However, revealing these tags does not determine whether your deductions are correct.

It is also important to remember that the person pulling the Trigger is the player, not the protagonist.

Because of this, the Trigger System itself has no success or failure state. It merely provides the information you choose to collect. Only after gathering your evidence do you attempt to solve the mystery.

This brings me to another important point.

Crimsooon Sun has no multiple endings and no game over conditions.

Even if your deduction is completely wrong, there is no penalty, and the story never changes. If you solve the mystery, then you have solved it. If you fail, then you simply failed to solve the mystery. That is how detective novels work.

To avoid any misunderstanding: this is not a trick, and there is no hidden route or alternate ending. Your deductions do not affect achievements either.

So please feel free to experiment with the Trigger System and enjoy solving the mystery in your own way.

Demo

The demo will be available at the same time as the full game.
The demo includes the entirety of Chapter 1.

Any save data created in the demo can be carried over directly to the full version.

The game consists of three chapters, each of roughly the same length. As a result, the full game should take approximately three times as long to complete as the demo. If you would like to get a sense of the game's overall volume and pacing, the demo should provide a good impression.

In total, the game contains approximately 87,000 words of main story text and Trigger Notes, plus around 30,000 words in the deduction sections.

Of course, players will not necessarily read every Trigger Note in full, and the deduction sections depend on how much time you spend thinking through the mystery. My rough estimate is that the average amount of text read during a playthrough is comparable to a single paperback novel.

There is no major post-game content after completing the story. However, one additional Trigger becomes available in the Prologue after finishing the game, and the limit on the number of Triggers you may use is removed.

Bug Reports and Feedback

If you encounter any bugs or other issues, I would greatly appreciate it if you could report them in the thread linked below. Reports are welcome in both Japanese and English.

https://steamcommunity.com/app/4631660/discussions/0/569291508114600377/

Please feel free to report any missing text, typos, unexpected behavior, or parts of the interface that feel difficult to use.

I would especially appreciate feedback regarding controller support.

My goal was to make the entire game fully playable with a controller. However, during Steam's review, they encountered a section where controller input stopped working. Unfortunately, I was not told exactly where the problem occurred, so I have temporarily removed the "Full Controller Support" designation from the store page.

If you find any part of the game that cannot be operated with a controller, please let me know.

I also made one audio adjustment for the PC version. Compared with the mobile release, I increased the volume of sound effects and ambient sounds relative to the background music. After listening to it repeatedly during development, I found it difficult to judge whether the balance is appropriate anymore.

If the sound effects feel too loud, or, though I think this is unlikely, too quiet compared with the background music, I would appreciate your feedback on that as well. The background music is only played during the scenes set inside the café (through the in-store speakers).

Thank you very much for your interest in Crimsooon Sun.

I hope you enjoy solving its mystery.
Even if the heavenly spheres never cease their motion.