If Konami would give me the rights to do it, I'd make a Yu-Gi-Oh! Video game using AR cards, like the 3DS AR Games.
Or I'd make a video game where you play as a character with animal based super powers. It'll be a side-scroller, You'll navigate through the game using different animal body parts and your goal in the game is to rescue all of you team mates and gather test tubes with animal DNA samples to allow you to gain more transformations. Your enemies would be a bunch of pirate-goblin-knights.