This was originally made on Fantendo as a joke to make fun of something.
Pink Gold Peach & Metal Mario: Minerals in Time is an upcoming game produced and developed by Nintendo for the Nintendo 3DS. It is an RPG game.
Pink Gold Peach, Metal Mario, Baby Rosalina and many others are racing in on a Mario Kart track, when suddenly, a weird portal opens. It makes a sound and the three of them disappear in it.
Later, they wake up in a weird purple castle, which seems to be completely abandoned. They see a few weird creatures similar to Toads, but purple, and find out they are called Shroobs. They have to flee the castle, and in fact the entire world of the past, by travelling over all of the areas searching for a time portal pieces to restore it.
The gameplay works similar to that of other RPGs, especially to that of the Mario & Luigi series. They have to fight enemies to gain experience points, and in all of the main areas awaits a boss in the end, who guards a piece of the time portal for some reason.