What kind of file do you want? If you already installed the Steam version you don't really need the DRM-free version from here. Except if you want to play the game without Steam.
if Steam -> use Steam if not Steam -> download ZIP file from itch
Rest in peace. Is there a way to get a hold of the source files to continue his work? I know InDesign and Affinity Publisher, so if the files are in these formats, I could edit them.