Wiimote prototypes...

[A Black Falcon]

Well, lots of games don't use some buttons on a controller, but with the PSX controller, like the Genesis as I said, it's not just that games aren't using them but that they CAN'T if they want to be compatible with the older controllers too. And most games don't want to limit themselves by cutting off people who don't have the new controllers -- I think Ape Escape requires the analog controller for PSX, but I don't know of any others...