It seems the new video game format now is that the game is free, but you are motivated to buy in game currency to buy powerups to win. What if we turned this around and the game was free, and if you played well you could win game currency that you could then trade for bitcoin or something else.
I know the games cost a lot to develope these days, but a very simple game, even if its just Tetris that pays rewards could find a big following. Think of it like Jeapordy. They give away about $20,000 a day on their show, plus production expenses, but still make money from the advertising.
So if a game could be created with advertising, then players could complete and play to earn actual money. Seems like this would catch on.