Parasyte over at GSCentral has discovered some very interesting things whilst tinkering with his Mario Kart game. Nintendo began remaking extra courses for Mario Kart DS, including Mario Circuit named "old_mario_gc" from Double Dash, an early beta Waluigi Pinball (presumably) named "luigi_course", and several more.

Of course, these courses don't contain textures, but Parasyte is working on it, so hopefully we'll have screenshots in the future of these secret courses, and with any hope, some of us may be able to play them.

This is really interesting news, Parasyte has stated he will NOT release this as it can lead to cheats which will ruin online game play.