Be like the wind
The gameplay in Shinobi is great, there are alway packs of enemies running at you, waiting to be slaughtered. If and when the action pauses for a second, a boss fight awaits. These fights are definately not easy, the bosses take a while to down and they always have minions to hinder your progress. You have a bunch of cool moves at your disposal, like the wall run, which allows you to jump up on the side of a building and run like the wind.
The graphics are nothing special. The constant buldings and cracked floors in the first couple of levels are pretty depressing. Shinobi seems to move fairly fluently.
The sounds are good too, explosions and stuff are heard throughout your progress through the game.
Once you complete the game, you could probably go back and do each level again to try and get A's, if you allready haven't.
While the levels can be cramoed and boring at times, this game is definately worth checking out purely for the challenge.