Sakurai unveiled a new level based on the original Mega Man series, Dr. Wily's Castle. This stage and a few others will play host to some boss characters that will spawn and attack characters.
In Dr. Wily's Castle, the boss character that shows up is the very iconic Yellow Devil, pictured above. Disposing him will be important since he not only packs a punch, but rewards the player that defeats him with a big explosion that knocks off any other players. Of course, players who are familiar with the Yellow Devil know that his main weakness is his red eye. Players can then choose whether to attack Yellow Devil directly, try to fight around him, or target the players who are trying to take him out.
Sakurai also teased a shadow of Ridley from the Metroid series as one of the boss characters that can appear in the stage, pictured below.