There is absolutely no comparison between the android ecosystem and the XBMC ecosystem. Android has many orders of magnitudes more apps than XBMC does.
More to the point, your XBMC box can run ordinary windows programs, of which there are many orders of magnitude more than android apps. Plug in an Xbox360 controller and you're playing on something very like what many existing games were designed for.
More to the point, your XBMC box can run ordinary windows programs, of which there are many orders of magnitude more than android apps. Plug in an Xbox360 controller and you're playing on something very like what many existing games were designed for.