ishiki on 09 February 2014
the things that take up the most amount of space are
High Resolution Textures, increasing the texture (Mario also uses a lot of flat textures, and reuses the same textures a lot, it looks good though).
It's more complicated than this, but just increasing the texture resolution from 512x512 to 2048x2048 can increase the size by 6x.
Uncompressed Audio
FMV's with Uncompressed taking even more.
There are many 10+ gb games that are shorter than super mario world.
