Thanks for bringing this to our attention! This was a simple goof on my part when zipping the 1.01 update. (I'm still relatively new to updating and maintaining stuff on itch and still getting to know the desktop client and working with the butler and all that.) I've uploaded a new version which should have things packaged appropriately.
I see that you've moved the 1.01 version of forevergold.html into the Forever Gold folder (replacing the 1.00 version), which makes the game work out of the box for those who manually download/extract it and run it in their web browser.
In the Itch Desktop client, attempting to launch the game still opens up the game's directory in the filesystem rather than launching the game itself. The Itch desktop client needs the HTML file to be either in the root directory or named in a manifest file; otherwise, it doesn't know what file it should be trying to launch. (In your case, adding the manifest file would probably be the easier fix, unless you'd rather edit the HMTL file so that it can run from the root directory of wherever it gets extracted to.)