The term "highly compressed" in the context of PSP games usually refers to versions that have been optimized to take up less storage space, making them more accessible for download or transfer. While specific compression details might vary, a highly compressed version of Crisis Core: Final Fantasy VII for the PSP would ideally retain the core gameplay elements, story, and graphics while being optimized for a smaller file size. This allows players with limited storage or those preferring digital downloads to enjoy the game without any significant compromises.