Mario's Face (lost Nintendo DS tech demo; 2004)
Mario's Face was a Nintendo DS tech demo that was developed by Nintendo EAD and shown at E3 2004 to display the capabilities of Nintendo's then-new system.
The player could select Mario or Wario and then use the stylus on the touch screen, grab parts of Mario/Wario's faces, and pull and stretch them, similar to the Super Mario 64 title screen and, to a lesser degree, the Mario Party "Face Lift" minigames. This feature was also put into Super Mario 64 DS, albeit in a far simpler form.
This particular demo hasn't been shown since its E3 presentation and has not been dumped online.