Musashi Ganryuki
I also love the game and consider it to be one of the best "home console style" NEOGEO titles. (there were not that many really anyhow) And certainly, one of the most original and very involved too.
I wrote a really good thorough review for the game over ten years ago (for another website). I will post it here in a little bit when I find it.
A little bit of additional unknown trivia while you wait for the review, the game also had a version for the Sega ST-V system.
EDIT: Here is the original review:
August 27, 2000
NEO NINJA GAIDEN
One of the best platform games ever made was the NES version of Ninja Gaiden. It spawned two sequels on the NES, which were both equally impressive as well as a great SNES compilation-cart appropriately titled Ninja Gaiden Trilogy. The series went down in history as one of the most entertaining games ever produced. Nothing like the arcade version (which was actually a double-dragon style beat-um-up, this game created a huge following and pretty much put TECMO on the map.
A lot of us have heard the rumors surrounding a Ninja Gaiden game having been made for the NEOGEO AES. And with TECMO having been one of the third party licensees for the console (Tecmo World Soccer ’96) it is a rumor which would seem easy to believe. However I can provide strong evidence that the game was never made, but rather that its announcement was simply a case of mistaken identity.
Back in 1994-1995 VISCO used the development hardware to make 3 NEOGEO games:
(Battle Flipshot, Captain Tomaday, and Musashi Ganryuki)
However for some strange reason, VISCO never got around to releasing them. Some screenshots of the games did however slip out, one of them being of the game Musashi Ganryuki AKA "Ganryu". The main character in the game bears a striking resemblance to Ryu Hayabusa, the hero of the Ninja Gaiden series by sporting the typical blue outfit and carrying the bladed sword.
Anyhow, put two and two together, and one can easily see how such a mix-up would occur. A screenshot of what is a platform game showing a character sporting the same outfit as RYU hayabusa…and the games name gan RYU.
It makes PERFECT sense that the conclusion or theory could have been made.
Anyhow, fast forward to present day (1999), amidst SNK’s much more liberal policy towards 3rd party games, coupled with Visco’s desperation to close shop with the least possible financial disarray, as well as a much larger Asian and European market, and voila…SNK decides to go ahead and release the software titles. Since at the time, SNK’s current "board-set revision" happens to be the GIGA-shock style, despite being way less then 500 megs, the titles are released under the label.
The first releases, Captain Tomaday and Battle Flipshot make it off the assembly line presses just in time before the changeover to the "KOF99" copy-protected board set…while Ganryu sadly does not.

As a result, they are NOT compatible with most current MVS to AES adapters. Therefore, the only way to play this great title as of this writing is either on an MVS board OR via a conversion cartridge.
I recently obtained this great game for my collection, and got the chance to play it. And so I just wanted to quickly give my opinion on it. In the sea of fighting games on the NEO, it sure is great to have a platform like this. The game is excellent. It has absolutely everything that makes up a great game. It has two intros, great backgrounds, great music, a large weapon selection, a good story line, alternate paths, hidden rooms, bonus items, checkpoint memory card saves, etc. Need I say more! The game plays and feels just like a ninja gaiden. It is so nice to have a game like this on the neo. Not since Magician Lord have I truly enjoyed this type of game play on my NEO.
I would strongly recommend the game to anyone who is looking for a sweet new title to keep them entertained for a long time.