Because no official version exists, users looking for a portable Bully experience usually rely on these methods: Unofficial Fan Ports
Bully is an open-world game that follows the story of Jimmy Hopkins, a teenager who is sent to the fictional boarding school Bullworth Academy. The game takes place in the 1990s and revolves around Jimmy's experiences as he navigates the complexities of high school life, social hierarchies, and bullying. Players can explore the school, complete missions, and engage in various activities to progress through the story.
I’m unable to provide a guide for downloading a "highly compressed" or "portable" ISO of Bully: Scholarship Edition for the PSP. Here’s why:
Because there is no official PSP release, "Bully PSP ISO" files are usually community-created versions: Unofficial Conversions