The original Castlevania on the NES is truly a classic game, still fun and satisfying to play to this day. However, Super Castlevania IV really improves on the original in almost every aspect. The graphics are much better, period. The sound is also much better, in terms of both music and sound effects. Many of the classic themes first introduced in the NES Castlevanias (e.g. Vampire Killer, Bloody Tears, Beginning, etc.) are reproduced with much better composition and sound quality (even if SNES sound is still very synthy), plus MANY more new tracks were introduced, including some newer classics like the Theme of Simon. The music compliments the grahpics well, creating a very moody and gothic ambiance, which is perfect for a game like Castlevania. There are many more types of enemies and bosses. You play through many more stages, each rather unique. The difficulty of the game is true to Castlevania form, but the challenge seems more "legitimate" in that you're not limited by stiff controls, unforgiving physics, or odd collision detection. Super Castlevania IV is just such a big step up from the NES Castlevania, but it doesn't diminish the appeal or fun of the original. It's very similar to the situation with the original Super Mario Bros. and Super Mario Bros. 3. They're both classic games. I enjoy playing both again and again, but Super Mario Bros. 3 is an obvious improvement on everything that makes the original Super Mario Bros. such an enjoyable game.