New Super Mario Bros.......... Gold?

[New Super Mario]

I found this and I think it has something to do with the 25th anniversary

http://www.nintendo.co.jp/ds/a2dj/index.html

I think it is either a remake or something else from the first one

 

[SolarBlaze]

As far as I can tell, it's just the exact same game repackaged in a gold case. It's nothing special, really.