An Idea, I love these topics.

[JesseRoo]

I had an idea, but I just didn't want to make it myself. Anyway, here it is.

Catch Cards Game (I can't think of a good title)
STORY
One day, Bowser devised a devious plan to lure Mario to his castle. He bought a catch card and went to Mario's house. Then he captured Luigi in the catch card! So Mario went to save Luigi. However, Princess Peach knew he would need help, so she gave him heaps of catch cards.
GAMEPLAY
You have an overworld, which is actually a standard platforming thing, and you can explore the world like this. When you see an enemy, you can use a catch card to capture him in it. Sometimes, though, the catch card doesn't work. Occasionally you will find enemies such as bosses and that kind of stuff who challenge you to a card game. This is the battle mode. You play a Yu-Gi-Oh style card game using the catch cards you have, and the winner can take one of his opponent's cards.

If anybody wants to make it, I may be able to help a bit in coding.

[Sharrach Duur]

Sounds cool.
Someone should most certainly make it!