I think it would be great if we had a Boomo that was 2 player.
I don't think it would require much change just a smaller map and and starts with 2 people.
Also it would be cool if you could create a wager with another player while in a minigame lobby.
It would just have a set price that both parties will pay and then if one wins the money goes to them and if any other interruption to game play besides leaving during the game while it is running or if neither of the two win then the money is returned or never leaves depending on how it is implemented.