A wave based mode of the game that provides the more experienced players the insatiable masculine urge to take a final stand as they are outnumbered.
With each 10 waves of enemies, a boss will spawn up until level 50, where it will then occur in increments of 50, then 100, and so on.
(The plank bridge behind the player in spawn covers a hole... How about we make it a secret entrance to this?)