I think the Robot Museum from MM7 would be an awesome stage if it had statues of the robot masters in it. Imagine turning a corner and seeing QUICK MAN! You shoot! But it was just a statue...then someone playing Quick Man comes up from behind and shoots you.
or you dress up like a character(like a download skin,like Uranus(dont make any jokes...)) and then they notice you,think "Wow,he put in a detailed skin,and maybe he forgot the colours."and then he quickly pulls out rolling cutter and BAM!You were fragged Megaman FTW!that would be cool