Just Excellent.
Unfortunately I have noticed that many people complain about the difficulty. Frankly I must agree. The game can be extremely frustrating at times. I found myself spending more time turning it off and walking away from it than sitting through and playing it. When you die in the game you must restart from the beginning of the level, no matter how much progress you made, which is, needless to say, very frustrating. The game is a good challenge but it definitely would've benefit from mid-level save checkpoints.
'Tate' kills are a nice little reward for quick multi-kills. They occur when you killed a group of 4 or more enemies in quick succession. When you kill all of them, you are treated to a brief in-game cutscene with Shinobi striking a pose, sometimes uttering a line, and then watching your enemies fall to bloody pieces around you (again, looking as if inspired by Japanese Animation.) These kills help to fuel your power and will increase the power of your weapon. However, in later levels Tate kills will become very necessary for you to survive, since your sword begins to consume your life. If you go more than 1 minute without killing an enemy, you will die. this becomes very frustrating, since it leaves no time for you to look for secrets. Tate kills also become nearly impossible in later levels since the enemies become stronger. Some cannot even be killed...many enemies requires lots of dashing and jumping to even do damage to their invincible blocking. These incredibly annoying enemies often take so long to beat that the other enemies die before the Tate can be completed.
Fighting enemies can sometimes become frustrating. The targeting system is pretty strange...instead of targeting the nearest enemy, it will target the enemy that is often farthest from you or is most directly in your line of view, often resulting in the closer enemies around you getting in some cheap hits. Sometimes in the middle of a combo, Shinobi will freeze in a pose, allowing other enemies to get a good 2 or 3 hits on you. Otherwise, the fighting just takes a little bit of skill and some getting used to, but you will enjoy it.
The commercial was right: Shinobi's back. And in a big way. This is definitely a good game but you must have a high threshold of patience. This game can become very frustrating, resulting in cheap deaths(especially in levels that are just packed with pitfalls) and unbeleivably difficult boss fights lead to many fights being done and over and over. Alot of the levels are very bland and very repetetive as well. But the game has a good story, told through some pretty good cinematics. The American voices aren't that bad either. Usually translated voices are pretty awful, but Shinobi has some decent talent (although the rogue ninja woman has an irritating 'school-girl' type of voice).
If you were a fan of Shinobi in the past, or are looking for a fast-paced action game with a decent story, pick it up. However if you are a casual gamer that isn't looking for much of a challenge, stay away. The difficulty of the game will probably get to you rather quickly.