Basically, whenever you enter a mirror, the world is reflected, but your motion continues." ([/font][/color]http://awesomegameideas.tumblr.com/post/48815055810/idea-2-mirror-platformer)
I don't know why, but this sparked the following idea:
How about a game where you can only use one sense at a time? So you can see see but not hear or feel, you can hear but everything is pitch black or you can feel the rumble of the controller but nothing else.
Smell og taste would probably be too grose to incorporate :-)