If you meant for a direct bitcoin currency in that game, it's not possible since no way the developer will earn money from that if they will not implement their own currency in-game. Unless they will open an in-game store of equips,items,spells etc where you can purchase it directly with bitcoin without using their own in-game currency (e.g. diamonds, gems etc.)

But for purchasing a bound currency in-game which can be purchase thru bitcoin, that is possible.