Apparently I didn't make the comment very clear: he should build a webapp instead. Make it a game if you want, but build it outside their walled gardens.
But web-based games/apps don't sell very well at all, compared to iOS and Android native apps (even if the native are built with the same web technologies).
Unless it's a service website, the monetization for web apps just isn't up to par.
Unless it's a service website, the monetization for web apps just isn't up to par.