Creator of Mario, Shigeru Miyamoto, sent the game's developers a fax with suggestions for the game. The first suggestion was that there was too much close-up killing, which Miyamoto found to be unbearable. The second was to have the player to shake the hands of all the hospitalized enemies at the end of the game.

This suggestion gave the developers the idea of having all of the game's characters appear in a curtain call during the end credits, as if portrayed by real actors. This was meant to explain that the game did not involve real killing.