Castlevania SD for Mesen (left) VS Castlevania 30th anniversary for Nestopia (right).

Castlevania SD uses graphics from Castlevania for mobile phones generation 2, released in 2003 by KONAMI
The soundtrack is modified. Ogg track sources are indicated in their respective tags. Mostly they are fan remixes:
Stage 1-17 themes are by Jorge D. Fuentes
Stage 18, boss fight, stage clear, and final themes are by Skeletroy
Intro theme is by themusicprophet003
Game over and player miss themes are by KONAMI
Download link:
www.romhacking....
Castlevania 30th anniversary uses graphics from Castlevania for mobile phones generation 2. The missing tiles are taken from Vampire Killer for MSX, Castlevania Bloodlines for Genesis, or touched up manually. The soundtrack remains original.
Download link:
www.romhacking....
The video is recorded with the game played in easy mode. The purpose is not to show my skills (which are weak), but to help you choose the pack for you.
In order to use the Castlevania SD pack you have to download it and then:
1. Download the latest Mesen emulator (0.9.6 and up) from www.mesen.ca
2. Load your Castlevania NES ROM into it.
3. Install one of these HD Packs using Mesen's Utilities--Install HD Pack menu option.
In order to play Castlevania 30th anniversary you should:
1. Download the modified Nestopia emulator from the link above
2. Load your Castlevania NES ROM into it.

[@oktoberbabyfee]

Don't be messin' with da Mesen!

[@Flpstrike]

Nice, Simon looks more like Simon a lot more now

[@kya6568]

Actually, Simon is the same in both of these versions. The difference here is in the background tiles. In the 30th anniversary version each individual tile is redrawn, but the arrangement of the tiles is exactly the same as in the original Castlevania. The benefit is that you may use this pack with level hacks of Castlevania, and they will be rendered correctly. In the SD version not the individual tiles but the entire backgrounds get replaced. This allows to add some extra detail present in the mobile version, but makes the pack incompatible with level hacks. Another difference is the music. 30th anniversary version contains the original 8bit music. SD version has an updated soundtrack arranged by Jorge D. Fuentes.

[@ruminator3570]

Visually it's better, musically not so much. However I salute and appreciate the effort. I admit it's better than anything I can do and I thank you.

[@flyinyoku3543]

Once again a fan does it better than the actual company 😂

[@விஷ்ணு_கார்த்திக்]

To be fair, Konami isn't doing anything with Castlevania lol

[@kleytonfacundo]

O que é um mesen?

[@igodreamer7096]

Nome do emulador para NES/Nintendinho.