: Use ZArchiver or a similar tool to extract the contents. You should see an .ISO or .CSO file.
Any "100 MB" download is likely a fan-made modification (mod) of official PSP titles, such as GTA: Vice City Stories or GTA: Liberty City Stories , which have been reskinned to look like San Andreas. Understanding the 100 MB PPSSPP "Mod"
Because San Andreas was never officially ported to the PSP, community developers create "Lite" versions using textures and assets from other games.
: These versions use heavy compression tools like ZArchiver to shrink the ISO file into a highly compressed ZIP.
