I'm amazed to see Ninja Gaiden on this list. I've NEVER heard it compared in that way to Castlevania before. Sure, the two games fit in to a sort of sub-genre of action oriented sidescrollers, which included many that shared similar life bar systems. To state the differences between the games, such as "the ability to cling to walls", among other things, then to state the game is "unoriginal" is ridiculous. The two games were very different. Honestly, if anything is a "rip-off", it's NATSUME's BLUE SHADOW being a rip-off of Ninja Gaiden. And certainly if anything on the NES is a ripoff of CASTLEVANIA it's Bandai's FRANKENSTEIN. Also noted is their failure to recognize that Ninja Gaiden was originally an arcade game.