On that note, I recently ported one of my HTML5 jam games to the
Firefox marketplace, which in addition to having mobile platforms (Firefox OS), also means it's available for PCs, although Firefox is required.
The level of effort needed is similar: mainly writing a
manifest JSON, although I had to take a short content-rating quiz also. I imagine it would be a similar amount of effort for other platforms like the chrome store (requires $5 registration).
HTML5 is a pretty good games platform; I'm seriously considering using it for most of my new projects since it's so portable.