is a decadent sci-fi side-scrolling action-horror game developed by Nekouji Studio (often stylized as NEKOUJI). Initially released as a series of experimental builds and demos, including the notable "Final Demo" in July 2025, the full game officially launched on DLsite in August 2025 and on Steam in December 2025.
: Players control an amnesiac huntress equipped with a knife for close-quarters combat and a massive arsenal of up to 16 distinct guns . cyan brain demo 81 nekouji studio
As an adult-only title, Cyan Brain features explicit depictions of violence, sexual acts, and gore. The game includes themes such as interspecies encounters, mechanical assaults, and "ryona" (focused on the suffering of characters) with approximately . Accessing the Demos and Updates As an adult-only title, Cyan Brain features explicit
: Players must manage resources; eating food increases hydration, which automatically generates healing items at maximum levels. : The game takes place in colossal ruins
: The game takes place in colossal ruins and research stations choked with deranged machines and grotesque aberrations.
: Successful hits trigger random, realistic blood-splatter effects. As the protagonist takes damage, her outfit progressively tears, reflecting her increasing vulnerability.