A recent patent filed with Miyamoto credited as an inventor revealed one of his unused game ideas.
The DS is a platform that features many role-playing games, however not many of them exploit the DS's unique features. A recent patent revealed that Miyamoto has an idea that blends traditional RPG conventions with the unique traits of the DS.
Like a normal RPG, enemies randomly attack players, however the combat is completely touch screen based and presented in a first person view. To attack enemies in battle players simply tap on the enemy with a stylus or a finger. Enemies take damage if the players successfully hit the enemy, and the amount of damage depends on where the enemy was hit. For an example: hitting a weak point will yield more damage than a normal hit to the torso, if a shield is hit then the enemies will take less damage than normal. The challenge comes from the movements of enemies around the screen. If the players miss then so does the attack.