I haven't had a experience similar to this in years. It is almost too perfect to believe.
Gameplay: 10. Action adventure games can be very bland sometimes, but this game rewards you for being a top notch gamer. There are some rounds where you will do great and kill all of the enemies, and some rounds where the first enemy will finish you off.
Each round (every restart from the last save point) is unique and you must be quick to kill the enemies or they will get you. The wall running makes it more complex yet it is vital to your survival. It is possible to do the swooping crane technique over and over and win however, but it is still a flawless combat system. AI is smart, and knows how to piss you off.
Graphics: The character models look great, and all the weapons look very cool. There are no graphical flaws that I can think of. The cutscenes look incredible, they are just plain good to watch. The world itself looks very real too.
Sound: Every sound effect is fine. I especially love the nun-chuck sounds. The music can get slightly repetitive, but only so because of the number of times you have to replay certain spots.
Value: Although the game's story isn't as good a second time, you will replay it at one point or another. There are always items that you may have missed, or maybe you want to try using a different weapon.
Tilt: The mixing of all of these elements into one amazing game makes the tilt a 10. It is a unique title that accomplishes what many other action adventure games try to do - to be challenging, intense, and fun. Many others fail in one of the aspects, but Ninja Gaiden excels all around.
You will love it. I haven't played Ninja Gaiden Black, but apparently it is even better.