Having the (loud as heck) music start playing as soon as I load a game's webpage is NOT ok!
Having it then be some HTML5 game that I wasn't aware was an HTML5 game because 'Web' wasn't marked properly is another issue.

HTML5 games on the itch.io main website need to be forced to always be CLICK TO PLAY.
I'm starting to regret telling others about itch.io or promoting any of these itch.io games if the website can't be bothered to put in such a basic consumer-facing feature into their service.

I thought nowadays games default to that when you create a new one. Those published a while ago might still have the old setting though. For what it's worth, you also have a checkbox in your account settings that forces all games to be click-to-play, but it only works when you're logged in.