Its not as groundbreaking as you think (or I think).
If the CAI generated from the game can be transferred to your wallet and then eventually exchanged to btc/usd then that would be groundbreaking.
Tho things attached to that like gold farming etc will be abused so people can make money which would lead to the currency be next to worthless.
It be groundbreaking if even with the abuses, the currency keeps its value.
That can be done with an android app maybe, but apple is very strict about crypto currencies. Exchanging ingame credits or coins into crypto is not hard to integrate, but there would be a lot of legal problems to deal with. Maybe in the near future as laws in the US and other countries become clearer we can quickly apply that by updating our game servers.