I don't really care about the encoding, it was just the point that you can't use any other media with it. At the time, Playstations could play CDs, the PS2 had CD/DVD, and the xBox had CD/DVD and I think MP3!
The Game Cube was modeled after the Sega Dreamcast, in that you can use a hand-held as your controller and have an independent screen in your hands.
ehm, there were two games that I remember to use that, FF crystal chronicles, and zelda four swords. Both were really fun, but they weren't driving points for the gamecube really. The dreamcast accessory had a horrible lifetime too, and it wasn't essential either.