The term “highly compressed” is often associated with scene groups and repackers. For Metro 2033 Redux , the releases historically come from three trusted repackers (Note: Always support developers by buying the game when possible; this information is for educational/archival purposes regarding file compression technology).
For players on low-end systems or those trying to squeeze every frame out of a "compressed" install, focus on these settings: metro 2033 redux highly compressed best