This is really really worth nailing down, because I’ve done things a few times and I still bungle it. In fact I figured I was probably being clueless about something too embarrassing to ask about.
I’ve been stung by a few things when uploading, and I can’t imagine everyone else has avoided it. It’s this: if I build for release and rename play.html to index.html and find a bug, then I build for a release again, my “new” index.html is overwritten. I also find I need to tweak the style.css file at times. This also can be overwritten.
My solution is to have a script that renames things as need be. This requires a batch file.
I suspect there are others better, but I’d also like to propose one thing that worked really, really well for me, for anyone else who runs across this: make a trivial project you can delete from itch.io. A one-room game. Don’t worry about the content. Set it to private and keep uploading it until you get it right. This includes anything like the effects for grooverland.
For me, this helped isolate the “upload the ZIP file with Index.html” bit to get it right.
Does anyone have screenshots of the options to set? I think the descriptions are good, but it’s worth nailing down. (If no one does so, I may try them myself once I upload my own parsercomp game.)