A little background…
Released in late 2001, about eight months after the arrival of iTunes, the original Apple iPod music player featured a mini version of the game Breakout.
Breakout was published in 1976 by Atari, where a young Steve Wozniak and Steve Jobs were involved in building the game.
Inspired by Pong, Breakout centers around the player moving a bar horizontally to prevent a ball from touching the bottom of the screen and bouncing it back up at a layer of bricks on the ceiling that could be broken to win the round.
Later versions of iPod software moved the easter egg (version 1.1 put it in the "Legal" menu for instance) and before long Apple made it easily accessible alongside other mini games baked into the iPod's software.