Genre: Dark Fantasy / Isekai (Portal Fantasy) / Psychological Thriller Target Audience: Young Adult to Adult (Themes of manipulation, survival, and desire) Logline: After a transport accident, a mild-mannered botanist awakens in a lush, alien dimension where the dominant species feeds on human vitality. To survive, he must use his knowledge of plants to create the one thing that can kill a Succubus: a poison that tastes like love.
True End: Requires collecting all five Forget-Me-Not Flowers to unlock a final scene revealing the human form of the character Kuro. 📋 Technical Information Developer Shimofumi-ya Publisher OTAKU Plan Platform PC (Available on Steam) Status Fully Released (as of late 2025) 🔗 Useful Resources
Mumasekai: Lost in the World of Succubi is a 2D side-scrolling action-platformer with Metroidvania elements that takes players on a perilous journey through a supernatural realm. Developed by Shimofumi-ya and published by OTAKU Plan , the game was released on September 12, 2025 Story & Setting The protagonist awakens to find himself trapped in the Succubus World
Reviewers from the Steam Community have praised the game for its solid gameplay loop, noting that it holds up as a fun platformer even without the erotic content. Positive highlights include precise controls and fair boss patterns, while some minor criticisms point to stiff movement in the very early game before upgrades are unlocked. Lost in the World of Succubi on Steam
Quality of Life Features: Designed for easy play, the game includes instant retries, fast travel from any location, and the ability to change difficulty at any time.
The narrative begins with the protagonist and his cat, Kuro, awakening in the "Succubus World," a mysterious dimension ruled by creatures that drain life force from human dreams. Unlike many RPGs with heavy dialogue, the story is told primarily through exploration and boss encounters. The central goal is simple: find and ring a magical bell to break the dream and return home. Gameplay Mechanics
The city watched, indulgent. There were rules—soft as smoke but binding. Names were bargaining chips. You could not leave with your full name if you had traded memory for soft mornings. You could keep a friend’s face, but not their story. You could barter a prejudice for an art, a trauma for talent. The succubi offered the world in versions: simpler, sharper, sweeter. Each version required a corresponding erasure.
