If you manage to track down a comprehensive collection of these PKG files today, you are unlocking the definitive way to play the game. The base game is arguably incomplete without the DLC additions.
Released in 2010, Harmony of Despair (HD) was divisive. Critics found it grindy and obtuse, but fans fell in love with its sheer density. It was a game built for the hardcore—requiring knowledge of enemy patterns, drop rates, and character-specific glitches to conquer "Hard" mode chapters. castlevania harmony of despair dlc pkg exclusive