Glad it's useful.
One thing worth knowing before you build the web version, because it changes the plan rather than just the work. itch cannot take payment for a browser playable build. Web games there are donation only. So if this is ever going to be a paid title, the shape that works is a free browser build sitting on the same page as a paid download, rather than the browser build being the product itself.
For the upload, itch wants index.html at the top level of the zip rather than inside a folder, and you tick the box that marks the file as played in the browser. Set the viewport to your real canvas size or the frame will crop you.
Since yours is already HTML and JS packaged for Android, what's most likely to bite is anything that assumes a touchscreen. Worth clicking through the embed with a mouse once before you point testers at it.