Mario's Face

Mario's Face was an unreleased tech demo for the Nintendo DS, based off of the face screen on Super Mario 64. It allows the player to alter Mario's face, as well as Wario's, using the touch screen and stylus. The top screen of the game It is believed this was an early version of Super Mario 64 DS' version of this screen, though it does have several differences.

Description
At the bottom of the lower screen, there are 4 buttons: One allows you to drag pieces of Mario's face, one allows you to contort their facial features, the third allows you to spin around the character, and the 4th button allows you to switch between Mario and Wario. On the top screen, you can see Mario and Wario running around and interacting with the environment with sprites reminiscent of Super Mario Advance. Text displaying "MARIO'S FACE Tech Demo" can also be seen on the top upon initially booting up the tech demo, along with instructions on how to use the 4 buttons and controls.

Super Mario 64 DS Manifestation
In Super Mario 64 DS, this screen is replaced with Mario and Yoshi (who occasionally appears with a heart) being turned into drawings the player can mess around with, or just draw something entirely new. Wario is not present, but Luigi can rarely appear on this screen with an exclamation mark and shocked expression, replacing Mario, as if they were not expecting the player to find them. However, in some personalized copies, not only can Wario appear in drawing form, but it can reportedly be replaced entirely with Mario's Face, just with the Super Mario 64 DS logo on the top of the screen instead. How this occurs is unknown, as the data for Mario's Face is not in Super Mario 64 DS.