Damn, I even just checked one of their installers to be sure. It is an archive, it can be opened with 7-Zip, but the contents are not directly accessible files. So still either Wine to trick the downloader/installer, or install on a friend's computer and copy the files over. Although with GOG at least you can probably send them an e-mail with the situation, and they might put up a zip file people can download for just the data.