Valve never released an official port of Counter-Strike for the PSP. The versions available today are community-made homebrew titles built from scratch or running on modified game engines.
: Versions range from the classic v1.1 to v1.92, which improved UI and map quality. How to Install psp counter strike download
A high-capacity card (or a MicroSD-to-Pro Duo adapter) with at least 100MB to 500MB of free space, depending on the version and custom map packs you choose. Valve never released an official port of Counter-Strike