I wanted to bring the design list's attention to the new Wikipedia Adventure project, which you can now pre-alpha-test. It uses GuidedTours functionality to provide "an educational, interactive, web-game using a simulated Wikipedia interface which leads new users through a series of realistic 'missions' to familiarize them with the mechanics, navigation, philosophy, and practices of actual editing."
https://en.wikipedia.org/wiki/Wikipedia:The_Wikipedia_Adventure
More information: https://meta.wikimedia.org/wiki/Grants:IEG/The_Wikipedia_Adventure/Timeline
Thoughts on badges, game dynamics, incentives, and motivation...: https://en.wikipedia.org/wiki/Wikipedia:The_Wikipedia_Adventure/Research
The main creator, User:Ocaasi, would love your feedback! https://en.wikipedia.org/wiki/Wikipedia:The_Wikipedia_Adventure/Feedback