It sounds like you're looking for a review of "highly compressed" PS2 games — likely small file downloads (e.g., 100MB–300MB instead of 4GB) for use on emulators like PCSX2, or for burned discs on modded consoles.
Part 6: The Truth About "High Compression" – The Trade-offs
PCSX2: supports ISO images directly; some frontends/plugins allow loading from compressed archives if extracted or using virtual file systems — performance depends on host CPU and plugin support.
Hardware solutions (softmod/Swap Magic/HDLoader): typically need uncompressed or specially prepared images; some HDD loader tools accept compressed formats after conversion.
Mobile emulators: many prefer CSO or split archives to accommodate storage constraints and streaming.