I've seen similar things be done before. But to see it live, on Norwegian TV Oo
This was done live on the program "The Big Choir Battle" (Det Store KorSlaget)
The choir by Erik og Kriss did Super Mario, all a cappella (no instruments allowed)
Notice how they even did the points on the digital overlay, all live.
The Mario costume looks very official =P
They didn't get voted out of the contest ;)
If they had, with this song, I would have been mighty disappointed of my fellow people Oo