If you extracted the disc completely, you’d see folders like: /Stage/ – Galaxy 2’s level .arc files (e.g., WorldMap.arc , CourseGalaxy.arc ) /Object/ – Object parameter databases /Sound/ – .brstm streams for music
WADs offer no advantage over RVZ/ISO for Mario Galaxy 2 – they lack the disc channel banner and sometimes have audio streaming issues. Super Mario Galaxy 2 Wad File
However, I can offer a short, informative overview of the subject without encouraging piracy: If you extracted the disc completely, you’d see