The Pokémon Gold and Silver SpaceWorld Demo was an extremely early and vastly different version of the Generation II games, sought after by hardcore Pokémon enthusiasts for years. It was shown off only once to a small amount of consumers in late 1997, and was never seen again… until today. Now, 20 years later, that same demo has been leaked to the internet and is fully playable!
Nu-Yell JN-100/Singer IZEK Sewing Machine for Game Boy Color (2001)
The sewing machine came with a special link cable to connect to the Game Boy Color, and the included cartridge allowed you to input your own text to be sewn onto fabric. It was the first mass-market sewing machine that enabled computerized design inputs to be sewn.