Apple once designed a Tetris clone called "Stacker," with the game featured on a prototype version of the third-generation iPod. AppleDemoYT, known for sourcing rare prototype devices, shared images and a video of the unreleased iPod.
The iPod in question is a "DVT" device, which means it was a mid-stage prototype that was still in "Design Validation Testing." It has a model number of A1023, which is not a known model number of any version of an iPod Classic, and had custom serial interfacing designed by an Apple engineer.
The third-generation iPod was manufactured in week 14 of 2003 (over a month before the release of the third-generation iPod), and it was purchased from an electronics recycler in China that sold it as is for parts. The device was non-functional when it was purchased, but was able to boot when the hard drive flex cable was replaced.
The iPod runs a prototype version of iPodOS 2.0, and one of the games is "Stacker." Stacker works a lot like Tetris, where the Tetris pieces are moved from left to right using the scroll wheel. Pieces fall when the middle button is pressed, and the idea is to clear more lines at once to rack up points.
There are other games on the iPod, and all of them have placeholder non-release names, including Block0, Chopper, and Klondike. There's also a battery testing playlist on the device that has classical songs that play in a loop, suggesting Apple used this iPod to test the battery life of the third-generation iPod before it was released.
AppleDemoYT says that he asked "iPod godfather" Tony Fadell why the Stacker game was not released, and Fadell said that it was because games were added "with a later software release."
Apple did add several games to the iPod 3G over time, including Brick, Solitaire, Parachute, and Music Quiz. In 2006, Apple released games through the iTunes Store that people could purchase for later versions of the iPod, including an official version of Tetris.
Other games available through the iTunes Store included Bejeweled, Mini Golf, Mahjong, Zuma, Cubis 2, and Pac-Man, all of which pre-dated the App Store.
