Graphics: 6
It's hard to rate the graphics of this game. At first, it looks pretty dull. Even after venturing throughout all of the first level, the scenery is still pretty dull. Except there is a nice touch. Key items are likely to stick out, like the staff and the ninja stars. Also there are closed gates and manholes that flicker to show that they are passable. Very helpful.

Sound: 8
Of course you can't expect much from the NES. The SFX is unique, it sounds like you're in some martial arts movie with all the kicks and punches, except it's a little amusing.

Now the music is where this game went right. The intro is quite appealing, and the tune of the first level may get stuck in your head. If you reach further levels, then you'll know what I'm talking about.

Gameplay: 4
This is probably where the game did the worst. Fights are similar to RPGs: you kick the opponent a few times, he hits you back, you hit him some more until one of you is fallen, pretty lame and unreal. You probably will find more action trying to jump on the boats in the first level (which you should find quite irritating). Your opponents don't really die until you knock them down for the second time. If you find a good weapon, like the sword, then fighting will become a lot easier (which is really good).
The nice thing about the intro is that it shows you everything you need to do to beat the first level, except I recommend grabbing the ninja stars. It also gives you some clues on some items. Some I still haven't figured out.

Overall: 7
Yes, this game is playable. It's a good little adventure if you're into those games that requires figuring things out and jumping over obstacles. If you're expecting some good fights, you will not like it. The final boss is also irritating. If you want a clue on how to beat him: make sure all the candles are lit.

The Last Ninja is preety much a little better than what you'd expect from Jaleco, but not from Beam Software.