Heres an update for fans of the NES game:

Ninja Gaiden II: The Dark Sword of Chaos has been graphically enhanced! This graphics pack ports the graphics from Ninja Gaiden Trilogy for use with the NES version of the game and its 8-bit audio. It also goes several steps further than that. Graphical effects removed from Trilogy are kept intact (or “restored”), including lightning in Stage 3-1, ice glow in Stage 5-2, and fades in cutscenes. Various graphical anomalies and errors in Trilogy have also been fixed.
This pack is designed for use with the U.S. release of the game. It also requires Mesen v0.9.5 or later. As with other NES graphics packs, this pack needs to be extracted to Mesen’s “HdPacks” folder. All the files - .png files and hires.txt - need to be included in a subfolder in that directory with the same name as the game ROM being loaded. Make sure that “Use HDNES HD packs” is enabled in video options.
Enjoy!
Link to main project thread

via http://www.romhacking.net/forum/index.php?topic=26216