You may use any Mii character you want, however you must start with a Mii character that is at skill level ZERO for this event.
Begin the game and try to defeat as many opponents as possible. If you finish the first stage, proceed to the second stage, and so on... progressing through the stages in order. If you complete the first ten stages in order and you have still not been defeated on any stage, you may proceed through stages 11-20 (the reverse stages) in order. If you complete all 20 stages, your game is done. Your score is taken as your skill level achieved once you are defeated, or once you complete all 20 stages, whichever comes first. Once your game is done, some points may be added or subtracted based on the stage you just ended on, and your final score is taken after these points are adjusted.
In the event that many players begin to complete all 20 levels without being defeated, and if completed games result in the same scores... then scores will further be ranked by completed games in the shortest time.
No pausing is allowed. No breaks in between opponents are allowed.