The Nintendo GameCube release of F-Zero GX, released in 2003, has a secret buried within its diminutive disc: the high-speed racing game's arcade-only equivalent, F-Zero AX.
Utilizing an Action Replay Code and a series of codes, GameCube owners can experience the arcade version of the futuristic racer, booting into the F-Zero AX build. That hidden code was uncovered by F-Zero enthusiasts late last year, but was publicized today by RetroCollect.
F-Zero AX was released in arcades alongside F-Zero GX for GameCube. The game was developed by Nintendo and Sega's Amusement Vision team, with Shigeru Miyamoto and Yakuza director Toshihiro Nagoshi co-producing. Plugging a GameCube memory card into the arcade cabinet served to unlock tracks in the console version.
Check out a video of the F-Zero AX content being played in the video below.