The digital-only era of the PS3 was experimental. Many games were published, caught in licensing hell, and permanently removed from the PlayStation Store. For these titles, the original PKG files are the only surviving copies.
The "holy grail" of obscure PS3 software—a game that was cancelled days before release, with only a few physical and digital "packages" ever leaking. Delisted Games: Titles like Scott Pilgrim vs. The World: The Game (before its re-release) or
Obscure PKG files typically represent content that is no longer available on the official PlayStation Store or was never released to the general public. 1. Delisted Digital Content