About
Touhou Project is a long-running bullet hell series created by independent Japanese developer Jun'ya "ZUN" Ōta, who has published 20 mainline games and 13 spin-offs since 1997 under the name Team Shanghai Alice. ReC98 aims to perfectly reconstruct the source code of the first five Touhou Project games (TH01 through TH05), originally released exclusively for the NEC PC-9801. "Perfect" here means the binaries compiled from ReC98's code are indistinguishable from ZUN's original builds, verified on every commit. It does not include any original PC-98 asset data, so running the compiled executables still requires an existing copy of the original games.
How it differs from the original
The main `master` branch reproduces the original executables bit-for-bit, bugs included; separate branches like `debloated` and `anniversary` rearchitect the code for readability and fix bugs while leaving other original quirks intact.
Getting started
Building requires specific vintage tools — Borland Turbo C++ 4.0J and Turbo Assembler, plus bundled helpers (MS-DOS Player and the Tup build system) — and is done by running build.bat. The resulting executables need the original PC-98 game data files placed alongside them to actually run.
History
The project is funded through ongoing crowdfunding and has shifted its focus over time toward detailed documentation of ZUN's original code via a project blog, with TH01's decompilation completed in August 2022.