When Castlevania: Harmony of Despair launched on the PlayStation 3 in 2010 (and later on Xbox 360), it broke the traditional Metroidvania mold. Instead of a sprawling, interconnected castle, Konami delivered a 2D action-platformer focused on 6-player online co-op, speed runs, and loot grinding. But the true longevity of the game didn't come from the base title—it came from the mountain of downloadable content.
Castlevania: Harmony of Despair (HD) is a unique, multiplayer-focused entry in the series that takes sprites from previous games (like Symphony of the Night, Dawn of Sorrow, etc.) and places them into massive, map-puzzle levels. The base game is fun, but the DLC is arguably mandatory to turn it from a short novelty into a fully realized game. Castlevania Harmony Of Despair Dlc Pkg
For those unfamiliar with the PlayStation ecosystem, a .pkg file is the standard installation package for PlayStation 3, PS4, and PSP content. In the context of Harmony of Despair, the PKG files contain two things: Unlocking the Night: The Complete Guide to Castlevania