GitHub and GitHub Pages are good for hosting web-based games. But they are at least one downside. After commiting an update of site they are refreshing so god damn slow rate (at least mine ;/, about more that 10h, i haven’t mesured it).
But. If you build game with .html file template (like Unity for example) you can commit such bundles on separate branch. Additionaly you can post Atom feed of selected branch on sidebar (update rate is ASAP, it’s rss ), and even link to tarball/zip of last commit.