here are two of my suggestions.
i would like the option to be able to play a game in full in one session. i guess this would be similar to the varying time limit. i just feel that if you are game for playing right now, and wan to finish right now, that if another player joins who is on that 24 hour move game, it totally kills that.
i noticed the maps show who's turn it is, well why not show who is currently logged into the map as well so you can see who is actaully currently playing.