Castlevania is considered a classic game on the NES by many. As for myself, I suppose it could be considered as such, although I'm actually pretty awful at the game. But for many, it's a nostalgic trip back to a time when game difficulty was based on how solid a gamer's actual skills were. It also harkens to a time when you had to press Up to walk up stairs. Castlevania was the first of many dark treks into the castle of the dark lord, the almighty Dracula, to defeat him once again, as part of the seemingly eternal curse held by the Belmont clan.
But for the hacker who calls himself "Dr. Mario", the original Castlevania simply wasn't satisfactory. It yearned for some tweaks here and there. The result is "Castlevania: Orchestra of Despair", a game that closely resembles Castlevania in terms of its gameplay and general level layout but differentiates itself with alternate graphics to create a more somber mood. Even the generic life bar has been replaced with skull symbols. That's bold. And the scenery is profoundly darker in tone at times, to the point where the background is almost pitch black. There are perhaps a few too many areas where a little illumination would do it wonders. Even many of the enemies have been altered, though usually just into some other scary creature.
However, this hack has a few flaws. The floating candles, which are whipped to reveal hearts or other power-ups, are still in their original locations, and occasionally are surrounded by stones, rendering them unreachable by foot. As well, at one point in the second stage, there's a floating platform that moves back and forth. In the original game, it would be imperative to use this to sneak across a dangerous chasm. In Orchestra of Despair, however, there is a pile of stepping blocks right below it, rendering the platform useless. And, most irritating of all, is that (in general) the stairways blend in even better with the background, making them difficult to nigh-on-impossible to see.
It's still an interesting hack, though perhaps made slightly more difficult than it should be. The intro says that it's not a hack, but a "film by Dr. Mario". Silly. Maybe a few screenshots will help explain things even better: