Are you using a program like WinRAR to extract the file? If you're using the built-in windows file unpacker it may not work right.
My best guess is you've got a wack download somehow. I'm not really sure what could be happening to cause this issue, but my recommendation is to delete your copy & redownload. If for whatever reason it doesn't work, this game is officially posted in the Discord server - we have download links to other file hosting sites that might be better for you.\
Edit: reread your last message - I would strongly consider looking elsewhere for a download. My recommendation is the Discord server because those are links that I posted. I'm always skeptical of other sites.