Here’s something you don’t hear very often; a producer taking responsibility for a title not doing well. That’s exactly what Keiji Inafune did. However, all he regrets is the title of the game.
The producer behind Mega Man and Dead Rising apparently feels that the reason Yaiba: Ninja Gaiden Z received a lukewarm reception is that it wasn’t released as an original game to be judged on its own merits. Inafune is convinced that he created a “great” game and is satisfied with its contents.
It sounds like Inafune thinks that attaching a Ninja Gaiden title to the game brought him all sorts of bad luck. Unfortunately, this also means that he doesn’t make much of an overwhelming majority of players finding flaws with the game’s difficulty and level design.