The other route was streaming. Apps like PSPdisp or FuSa ScreenShot allowed you to stream your PC screen to the PSP over WiFi. You could technically play San Andreas on your PC and view it on the PSP. But the lag was horrific (200ms+), the resolution was compressed, and it required a PC. This didn't count as "portable" gaming.
While the PSP struggled, the eventually received a "true" port of the Android version of San Andreas gta san andreas psp homebrew
Before celebrating the homebrew heroes, it’s crucial to understand the hardware limitations. The PSP (specifically the 333 MHz CPU model) was a marvel, but it had severe bottlenecks: The other route was streaming
Abysmal failure. PS2 emulation requires a host machine several orders of magnitude faster than the original hardware. The PSP, being weaker than a PS2, cannot emulate it. Even today, high-end PCs struggle with flawless PS2 emulation. On the PSP, PS2 emulators like Play! or PCSX2 never progressed beyond displaying a static logo at 0.1 FPS. But the lag was horrific (200ms+), the resolution