The author commented on their ko-fi: "there isn't much to say that would require a big writeup - a lot of the code is already reversed, and anything that's missing can be yoinked from ghidra decomp output and cleaned up, so it's just a matter of transpiling to a different language. plus much of the game's proprietary formats are thoroughly documented by the modding community. time consuming but quite easy if you're just patient haha"

Another poster commented that it was likely done with Claude.