Heard of a site called Duolingo? It’s a language learning site some of my friends use. It has some interesting gamification elements I think you should look into.
You get points and level up for playing lessons, and you get streaks for playing a lesson each day, for example.
As there get to be more lessons, and the lessons get harder on this site, you might find elements like that help to keep players going.
I also recommend the Extra Credits web series, for ideas on gamification and game design in general.
Yes! Actually I lived with the guy that develops their iPhone/iPad app. I’ve talked to him about what they liked about how Duolingo did their points and skill trees and what they wish they’d tried differently. There are definitely a lot of things we want to build that they’ve already done, but there are some where we want to play around with different approaches.
I love that video link you sent–thanks for that. So much fun game stuff to build!