Battle Mii (lost Wii U tech demo; 2011)
From The Lost Media Wiki
Battle Mii was a tech demo for Nintendo's Wii U that was shown at E3 2011. In the demo, two Miis dressed as Samus from Metroid run around a level while shooting enemies, targets, or each other. Additionally, a third player could control Samus' gunship and attempt to defeat the other two players.
In the 2012 Wii U launch title Nintendo Land, there's a minigame called "Metroid Blast" that expanded and refined the original tech demo. However, the original tech demo has never resurfaced.