10 Games Hidden Within Games
2. Geometry Wars (Project Gotham Racing 2)
There's an interesting story behind Project Gotham Racing 2's game within a game, Geometry Wars. It started out as a piece of software developer Bizarre Creations was using to test the Xbox controller, but the studio decided to leave it in the game.
When Geometry Wars proved just as popular as the racing game it was piggybacking on, it was given a standalone release under the moniker of Geometry Wars: Retro Evolved and even went on to spawn a series.
Since then, sequels Geometry Wars: Retro Evolved 2 and Geometry Wars 3: Dimensions as well as a spinoff titled Geometry Wars: Galaxies have been released for various systems.
The game that began life as tester software and later became an Easter egg has also inspired a wave of imitators, such as the PC clone GridWars.