Somehow I am not convinced that the game experience is a good match for Wikipedia.
In games, you try to do all "in game", so that your attention is fully devoted to the game.
To contribute effectively to Wikipedia, you need instead to do quite a bit of research outside of Wikipedia, and then write the contribution including the citations.
These seem to be very different kinds of activities. I am sure we could get people playing the games of "Nobody reverts as fast as I do" (or better, "the guy that reverts faster than his shadow", see if you know what I am citing), or "who puts the most links to other language pages", ... but I doubt we would be as successful with content creation.
Luca