Technically, no. The original God of War 3 on PS3 is roughly (uncompressed). Compressing a 35GB game into 200MB would require a magic algorithm that doesn’t exist. Lossy compression would strip the game of audio, cutscenes, and textures, leaving a broken mess.
There is no official God of War 3 for PSP. The PSP titles are Chains of Olympus and Ghost of Sparta . Any file labeled "God of War 3 PPSSPP 200MB" is either a modified ROM hack, a poorly compressed God of War (2005) or God of War II (PS2) conversion, or, most likely, a fake/malware. Proceed with extreme caution. god of war 3 ppsspp 200mb zip file7z work