The NES, when released in 1985, changed the way home video game systems forever, at least in the US. In Europe, SEGA and home computers were dominant.
Ninja Gaiden II was released by Tecmo in 1990. Tecmo decided to keep everything that fans knew and loved for the sequel, resulting in a highly difficult game that felt at home with the original.
Ninja Gaiden II remains a game that is not designed for novice gamers and provides a challenge that is for dedicated gamers. Ninja Gaiden defined the term "NES Hard" One to try out, but be warned, Ninja Gaiden eats 8-bit novices for breakfast.