Old-school.
If you're looking for a challenge, old school game play, or just some sweet ninja action, then this game is for you. It might be the hardest game I've ever played, its set up to be a straight forward challenge through the levels, and you're a futuristic ninja, I don't see what could go wrong.
Graphically speaking, the game is top notch for a PS2 game. It really is one of the best looking games of the last generation. It even has some decent textures, which was a rare thing at the time. Everything is really detailed, especially the character models. I never experienced a frame rate drop, which is important because the game play is very difficult and fast-paced. The thing that really stands out for me is the fluid animations. The way you move through the game just seem right, and very ninja-like, if that makes any sense. Plus your scarf seems like it had its own development team because its so detailed and has some of the craziest animations I've ever seen. This game is just gushing with visual style. There's well used blur effects, over the top gore, and just an awesome art design, that I find to be very appealing.
The soundtrack won't blow anyone's mind, but it fits the game's style well. It seems like a revamped soundtrack of all those old arcade games you loved to play as a kid. I find it to be especially awesome thanks to nostalgia. The sound effects themselves work just fine, no real need for improvement.
The game play is fairly simple, but hard. Not only do you have a small life meter that can drop quickly, but most of your enemies seem to have more life than you do, which wouldn't be that difficult except that you fight up to a bout 10 at a time sometimes. A cool twist, that also adds to the difficulty as well as the fun is that your sword will get stronger with the more enemies you kill, but if you go for a period of time without killing anyone, you health will drain. This helps to keep you in the action.
Unfortunately no game is without flaws. We all love a challenge, but sometimes Shinobi pushes it a little too far. Whenever you die, you have to start at the beginning of the level. Also, some of the bosses seem to flat out cheat. There's also not a whole lot of replay-ability. Despite its flaws, I consider this to be an awesome game. If you like ninjas, a challenge, or want to experience some nostalgia, then this is the game for you.