You need the PPSSPP Emulator.
If these files do not contain GTA 5, what are you clicking on? Based on the history of mobile piracy sites and ROM hubs, here is what usually hides behind those "Download Now" buttons: gta 5 psp iso download top 19
A. The "Modded Vice City" Trick This is the most common bait. You download a 1GB ISO file expecting GTA 5. When you load it up, you realize you are actually playing Grand Theft Auto: Vice City (or Liberty City Stories). You need the PPSSPP Emulator
B. The "CSO" Compression Trap Some sites claim to offer "Highly Compressed" versions of GTA 5 (e.g., 500MB) in CSO format. Red flags to avoid:
C. The Survey Scam This is the most frustrating outcome. Many of the "Top 19" sites operate on CPA (Cost Per Action) networks.
Searching for "gta 5 psp iso download top 19" exposes you to:
Red flags to avoid: