If you are using the ISO on an emulator like or a mobile emulator like AetherSX2 : Format : Once extracted, the file should be a .iso or .bin .
The term "Highly Compressed" usually refers to versions of the game modified to fit smaller storage footprints for easier downloading and use on mobile emulators like or PC emulators like PCSX2 . Rumble Racing Ps2 Iso Highly Compressed