The development team focused on expanding the scope of the original Underground. The most significant development shift was moving from closed, menu-driven tracks to an open-world environment known as "Bayview." This required optimization of the game engine to handle streaming assets on the GameCube’s proprietary 1.5 GB optical discs (mini-DVDs) to minimize loading times.
The term "ISO" refers to an exact archive copy of the data from a GameCube optical disc (NOD format). Technical details of the GameCube release include: Need For Speed Underground 2 Gamecube Iso Highly
Extracting the SOUND.AFS archive reveals 1,242 individual audio files: The development team focused on expanding the scope
Once you have your ISO, the real fun begins. The GameCube version is harder to mod than the PC version, but texture packs work beautifully in Dolphin. Need For Speed Underground 2 Gamecube Iso Highly