Overview

Cyan Brain is a sci-fi horror game where players run and are pursued, by futa monsters and more….

Before downloading, please be aware
Please note that the game contains graphic violence and adult content. 

Screenshots

Changelog

v1.1.1

• Bugfixes

v1.1.0

• New Dynamic CG Added (Unlockable After Clear)
• 2 New Monsters (Appear in Chapters 4 & 5 / Defeat Cutscenes Included)
• 2 New Weapons (Obtainable in Chapter 3 / Placement Changed)
• Mine System Implemented (G Key Deployment / Self-Destruct Mechanism Included)

1.01
New Additions
Added 3 new reward CGs
　┗ Unlocked after clearing Stage 2, Stage 3, and Stage 4
　┗ Already-cleared save data can directly view them

Difficulty Adjustment
Made Easy Mode even easier to clear

Weapon Adjustment
Improved performance of certain weapons

Map Improvements
Adjusted layouts of certain maps

Bug Fixes
(1) Fixed issue where collected battle data would be lost if the protagonist died
(2) Fixed issue where protagonist would not appear at the correct location after loading a save
(3) Fixed freeze issue when re-entering Stage 2 and talking to HS202
(4) Fixed random crash issues
(5) Fixed freeze when opening doors in maps
(6) Fixed issue where some enemies would freeze in maps
(7) Fixed issue where protagonist could still roll during NPC dialogue
(8) Fixed incorrect UI display when restoring HP
(9) Fixed missing collision in some map areas
(10) Fixed negative ammo count issue

2025-08-13
Full Release

Demo 4.0
N/A

Demo 8.1
Base/Story System/Content Update

Demo 6.14
♦ New weapons
♦ A device for replenishing ammunition
♦ A feature to expand the field of view
♦ Several new screen effects

*Please note that save data from the previous version will no longer be usable.

**Please be aware that this version is a test release and ma

How To Install Cyan Brain

1. Extract
2. Play

Cyan Brain Free Download