Heres a release you dont see everyday:

Last year’s Castlevania 30th Anniversary facelift patch was recently updated. It is now available in a form of an HD pack for the Mesen NES emulator.
This HD Pack applies to a NES version of Castlevania (USA non-RevA ROM only) and replaces its graphics with the higher resolution graphics from Castlevania for mobile phones. It also replaces the game’s music tracks with ogg files.
In order to use this pack you have to download the latest Mesen emulator (0.9.5 and up) from
Then you should unzip and run it. Mesen will greet you with a configuration window. Pay attention what folder will be specified there as a “Data Storage Location”.
You need to place the contents of this HDPack zip file into the [Data Storage Location]/HdPacks/[CastlevaniaRomName] folder (e.g “HdPacks/Castlevania (USA)” if you are loading “Castlevania (USA).nes”)
After extracting the HDPack you should enable HDPacks in Mesen.Tick the box at Options-Video-Enable HDNes HD Packs, and then load the ROM into Mesen.