: Missing all cinematics, music, and high-resolution textures.
The concept of a "highly compressed" version of for PC—specifically one small enough to imply "Gameboy" levels of storage—generally refers to unofficial, repackaged versions of the game found on various third-party sites. While the original title is a massive blockbuster, these "highly compressed" versions often aim to reduce the standard 24GB install size down to a few gigabytes for easier downloading. Understanding Call of Duty: Black Ops on PC call-of-duty-black-ops-pc-game-highly-compressed-gameboy
While there is no "Gameboy" version of the PC game, there were legitimate handheld entries released during that era: : Missing all cinematics