About
Touhou Project is a long-running Japanese bullet-hell ("danmaku") doujin game series created almost entirely by the solo developer ZUN since 1997, known for its cast of characters and soundtracks, released under a permissive license that allows fan-made derivative works. Taisei Project is an open-source, top-down bullet-hell (danmaku) shooter set in the Touhou Project's world, written in C11 with SDL3 and OpenGL, officially supported on Windows, Linux, macOS, and WebGL-capable browsers, plus an experimental Nintendo Switch homebrew build.
How it differs from the original
Taisei is explicitly not a clone or port of any Touhou game: it tells its own original story with entirely original music, art, gameplay mechanics, and codebase, made possible by Touhou's permissive license for derivative doujin works.
Getting started
Precompiled binaries for Windows, Linux, and macOS are available from the project's GitHub releases, and an experimental WebGL build can be played directly in a browser; building from source is also supported via the Meson build system on POSIX-like systems.