Hmmm I'm not sure. Those are going be itch.io issues and how it's transporting it. I would clear your cache and try again or run native. Sorry to hear you're having issues. HTML gaming can have it's hiccups for sure.
What os and browser are you using? I've been able to test on Windows with Firefox 121.0.1 (64-bit), Chrome 120.0.6099.225 and macOS Chrome 120.0.6099.234.