
This is a metroidvania game made in GameMaker Studio using YYC, so unfortunately, it is very difficult to modify these files, As far as I know, they are compiled/encrypted data.win files
UndertaleModTool is very good to edit GameMaker data.win files, however until now files using YYC are a real problem, I wonder if exist something for that with QhickBMS
https://store.steampowered.com/app/1203 ... Labyrinth/
https://github.com/krzys-h/UndertaleModTool