Metroid (originally known as Metroid-Morph Ball) is one of 9-Volt's microgames from WarioWare: Twisted!. It returns in WarioWare Gold as one of 18-Volt's microgames.
The purpose of the game is to tilt the Game Boy Advance or Nintendo 3DS to get Samus to the Missile Tank. The game's graphics and sounds are based on the original Metroid for the Family Computer Disk System. In WarioWare Gold, Samus may appear in her Varia Suit leotard from the NES version instead of her usual Power Suit.