On Reddit – r/FurryVisualNovel someone asked the same question. I suggest you join this subreddit.
Anyway here's a quick introduction:
– install the app and all needed plugins
– download and extract the windows version of every game you want to port
– press .py not .exe or .sh, if it shows open in joiplay press that and it should run.
If you have remaining questions, I created a site for joiplay here to make it broadly available. There is a link to a video included.
