Weirdly enough, I didn't discover this game because of Castlevania.
I actually discovered it with Wai Wai World 1 and 2.
(Now, I wonder if anyone has played those?)
And it's a great game. It could be a nice series.
But... now all hope is lost, even for a cameo.
Galamoth "I laughed the very first time I saw "Hadoukens" in the intro when I first played this on my NES emulator a few years ago."
I know it's impossible to not think of Street Fighter nowadays. haha
But actually, the Hadouken in this game is different, ken in this case means sword, different kanji, same sound.
In Street Fighter the ken in hadouken means fist.
Something like Wave Fist, while in this game it's Wave Sword.
Coincidentally enough, Street Fighter and Getsu Fuuma Den were released in the same year.