I think adding Chess, Checkers, and Playing Cards would be a great idea. Each would be very easy to add to the game, and a player could start a game simply by selecting a person and right clicking on the game they own. Playing cards could come in all kinds of different decks, and a few basic card games could be added.
Rubi-Ka could have a few game parks where people could gather and play.
lol if the programmers wanted to take the effort, they could allow us to play vs. NPC's for practice.