"Crimsonland," a top-down shooter originally released in 2003, has seen a resurgence thanks to ongoing efforts to decompile and preserve its original code. The game, which gained a cult following for its addictive gameplay, has gone through various iterations, including a remaster in 2014. The author recalls their own nostalgic experiences with the game, having played it extensively on a 56k modem. They highlight the significance of different versions released over the years, particularly the v1.9.8 version, which became famous for its powerful gameplay mechanics. The current project aims to rewrite "Crimsonland" while ensuring it maintains the exact behavior of the original game. The process started with an understanding of the game's binary structure and custom formats. By using advanced tools like Ghidra and coding agents, the author meticulously decompiles the game to replicate its functions accurately. They emphasize three guiding principles: full fidelity to the original game, no assumptions in function reimplementation, and independence from the original runtime. This approach ensures that even minor quirks and bugs from the original binary are preserved in the new code. Decompiling "Crimsonland" presents challenges due to the lack of preserved information in the binary, requiring extensive analysis through both static and runtime methods. The author details their use of Ghidra for its scripting capabilities, allowing them to streamline the renaming and understanding of functions. They meticulously document their findings in a name map, which helps track the logic behind their renaming process. The effort represents a significant step toward not just preserving a piece of gaming history but also understanding the mechanics that made "Crimsonland" a classic.