At Comic Con 2012, Pen Ward, creator of Adventure Time, said when you beat the DS and 3DS game, it would play a video of him in a chair congratulating you in beating the game in a similar fashion to the Pepsi Man. However, it was never added to the game. It is presumed that it is replaced with the Konami Code secret where Pen dances.
Contributed by GuineaHog
Attachment
Attachment
 
Video