Physical controls are all the rage, but they've got nothing on sound! OK, they have everything on sound, but that hasn't stopped Andreas Refsgaard and Lasse Korsgaard, a pair of "interaction designers and creative coders", coming up with this experiment where one can play Wolfenstein 3D with just their mouth. Loud noise warning: Be sure to turn down your speakers before hitting play!
The controls are straightforward. Whistling moves the character forward, clapping acts as the "Use" key, two different grunts turn you left and right and as for shooting? "Pew pew", of course!
Sadly, if you want to play it, there's no demo or instructions, though if you're dedicated enough I can imagine it's possible to pull together the hardware and software yourself.
Somehow, I don't see this method of game-playing catching on, outside of some specific circumstances. I for one would be afraid of hyperventilating or scaring small children during the more tense and action-heavy sections of your typical shooter.