I don't think games are a good tool for educating adults about new concepts, they are time-consuming and distracting. You could use them to teach kids, but why would you want to teach kids about Bitcoin in the first place, it's not like they will be using it till they grow up.
Adults play games to relax and have fun, and educational games generally have poor gameplay, so I can't imagine such game being popular.
I don't agree with you. Games are one of the most powerful ways to actually conceptualize new things. I believe there were few studies made that proven that learning gamification is better than just scanning through some text or listen to lectures.
Also why do we need to stop playing games if we're adults?
it will greatly depend on how it is implemented and the little description that OP included seems like the target is more of younger generation rather than adults.
and hatshepsut93 is correct, adults don't play game to learn stuff. they play for entertainment. for example you'd play Call of Duty to have fun and won't learn anything!