This is the most common scenario. You might find a file titled Forza_Horizon_5_PSP.iso on a file-hosting site. When you download it (usually a few hundred megabytes), you will find it is actually:
To understand why Forza Horizon 5 cannot run on a PSP, we have to compare the specifications. forza horizon 5 psp iso download
The PSP uses a proprietary mobile graphics library from the early 2000s, while Forza Horizon 5 relies on DirectX 12 and ray-tracing technologies. This is the most common scenario