Authentic PSP games are archived in either .ISO or .CSO (Compressed ISO) formats. They can also come compressed in a .RAR or .ZIP archive. If a download link gives you an .EXE or .APK file for a PSP game, do not run it.
The PSP hardware is incapable of running the actual HD-era GTA 4 codebase. Files claiming to be native ISOs for GTA 4 on the PSP generally fall into three categories: psp iso club gta 4 link
Total Conversion Mods: Dedicated fans have created "skins" for GTA: Liberty City Stories Authentic PSP games are archived in either