Golden.
You've either just seen & articulated - or freshly created - entire new realms of possibilities here...
The concept of creating an alternative, overlaying version of the site that could reward certain accomplishments... man, that's a BIG one... :-)
@roelandp has been creating some pretty interesting, fun, small apps... curious as to what might coming fusing your insight with his experience & creativity - and of course many others' ideas and skills, in the time to come...
I can see achievement badges easily being integrated pretty quickly to get the ball rolling. It's exciting to think of where this could lead. :)