It should work fine in browser! Controller support unfortunately varies quite a bit between browsers, and many browsers will just report any controller as "Windows PC", resulting in always-XBox controller prompts.
Chromium-based works best on desktop and I've even tested the game successfully on iOS, but you need a controller connected to your phone for mobile browser support... or a keyboard, I guess. The "WebGL not supported on mobile" overlay is from itch.io, as far as I can tell.