it shouldn't need an install- try extracting the zip and then opening the html file!
I think they’re using the Itch.io official launcher.
I also have the same problem.
Edit: here’s a screenshot of what appears when trying to install from the launcher:
we'll add a note saying not to use the launcher for this- it's just a zip file containing an HTML site, no installation needed! sorry for the misunderstanding, we'll add that.
