You might think it's neat that North American Club Nintendo members will net extra coins for downloading the digital version of New Super Mario Bros. 2, but Japanese fans get an even sweeter bonus: An entire game. Specifically, Japanese downloaders will get Donkey Kong: Original Edition, which features a factory level not found in the original NES release (pictured).
As Wired notes, Donkey Kong: Original Edition has never been sold, though it was included as a pre-installed Virtual Console game on the Mario 25th Anniversary Red Wii bundle in Europe.