This is half-baked idea but I was thinking of a variation on Blitz in the vein of the Resident Evil series "Mercenaries" and Call of Duty zombies game types. It would be somewhat like the mercenaries mode a few other forum goers have written about but starting in a smaller map. Destroying waves of progressively difficult bots in successive streaks adds seconds to the clock, unlike standard Blitz modes. While watching a friend play through the tutorial and noticed smaller, unreachable rings beneath the Grandma Betty's arena. As the player or team progresses they would be given the opportunity to open up more and more parts of the map, CoD Zombies-style. Anyway, yeah.
