Counterstrike on PS2?

One of my friends tells me he had Counter-Strike on PS2. I didn't believe him until he sent this pictures. My question is how Counter-Strike works on PS2. And how can I download it? I have thought of copying the ISO from my friend, but he said the disc is not working anymore. And told me that pictures he had took them before the disc broke. Does anyone know how or where to download it? I want to try it (: