The "highly compressed" PS2 ISOs you see online (often claims of 500MB for a 4GB game) are almost always a or a technical misunderstanding. The Reality of Compression
If a 4GB game is advertised as 10MB, it is likely a virus or a "fake" file. Genuine high compression usually reduces a game to about 20%–40% of its original size. ps2 iso highly compressed for android verified