I did not know this existed, but now may well of been gone on most devices. I saw this on the BBC website.
The device has to be a certain date, and then by doing the gesture of Mr Iwata then the game appears. It is the retro golf game that was programmed by Mr Iwata.
You can get all the details from the following link http://www.bbc.co.uk/news/technology-42502580
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