I've heard this is based on Shadow of the Ninja, but I have not played that game, so I can't make comparisons there. As a Ninja Gaiden fan however, this made for an interesting playthrough. I think this is even easier than the Master System game, hilariously enough - I made it to the final form of the final boss in a single credit, which really does not feel like it should be possible in a game with the Ninja Gaiden branding. But regardless of the lack of difficulty present here, I do think this is fun to play. It's got a good variety of enemy encounters and level hazards, and the music can be pretty great. The grappling hook is a curious feature, though it can be a bit cumbersome to use in a pinch. Overall however, this game is solid enough for playing through in a sitting.