ummm I think it's called "project unknown tester" once you unzip the file. It's the only link in the discord that's not the current version that has a valid download link. I believe for project unknown there are 3 versions? Or atleast that's as many as I could find when it was more available about a year ago. There was a test build (skeleton build with just one enemy and one scene), a tester build (with sandbox and free roam), and prototype(?) (free roam only). But yeah to your point, there are so many builds, project renaming, and project migration, it's hard to know what's going on unless you read through years of posts in discord or here.
Edit: oh yeah to find the link in discord search "mega". There aren't that many to look thru.