While the original NES Ninja Gaiden was tough, the first 3D take on the game was so hard that the developers re-released it a year later under the title 'Ninja Gaiden Black' to ease the pain of players. Why is that not on the list then I here you say? Because with the Ninja Gaiden Black release the general difficulty of the lower levels were decreased - nearly as a sarcastic swipe at the players pride - however, the rest of the game was actually amped up, big time. The many bosses of the game are so hard that most average gamers can't even get past the first without hacking and slashing their way to at least a thousand rage-fuelled deaths first. It nearly requires actual ninja skills to get through this unscathed, and by that I don't mean in the game.