Oh man, there are tons of hacks and mods for it too. My favorite being the retranslation one - fixes so many cryptic errors that we had to figure out back in the day. Almost a new game.

I played it again this weekend via that Anniversary Collection Konami released recently. Still a fun game and worth playing. I personally have trouble with the other Castlevania games - I just cannot get into them. I can Bloodlines though - I loved that one but the others on NES? Forget it. I think it may have something to do with all the knock back hits/pits you have to contend with.