In the context of GTA San Andreas, "deep features" could refer to advanced modifications, in-depth game mechanics, or high-level details within the game that aren't immediately apparent. This could include things like:
Vanilla SA stretched horribly on a 1080p monitor. A high quality version includes and a Widescreen Fix that corrects the Field of View (FOV), HUD alignment, and radar scaling. gta san andreas filecr high quality