Ok, seriously?
The GS score is one person's opinion. This is also one.
At first it seems a tad bit weak, mostly because the game does a less than stellar job of familiarizing you with your ninja's abilities. I mean beyond the tutorial. There's a large amount of skills you'll be using not too far into the game that you had no idea were coming, such as the 1-3 second rush, wall running, crawling along the ceiling, mimic-ing the voice of other guards and so on. So the initial impression for most people tends to be "There's only a single, 3-hit combo?! THIS GAME SUCKS! 4.9!" A. There ends up being around a dozen combos, 5 of these combos you map to the keys after purchasing them. B. If you're worried about playing this game like Ninja Gaiden with button mashing intensive combos, maybe you should go play that instead (which is also awesome, but I digress.) Repetitive? Sure it can be. But I tend to play for fun, not to see how many corners I can cut to finish the level "in 30 seconds by simply running by everyone." That... really makes no sense to me as to why you would do that when the levels in the game clearly present you with a whole buffet of victims to stalk... unless you find selling yourself short more fun for some strange reason. But hey... to each their own I suppose. I'm also not sure what else Aaron Thomas would have you be doing if not assassinating people. Driving buses perhaps? I was actually glad that I didn't get stuck with some absurd "Protect X while being chased by Y and killing eleventeen million zombie demons" mission. You're a ninja, you assassinate people. Constantly. And the A.I. is pretty much on par for stealth games, in that if they see you, they give chase, may call for help, look around while you evade them and then go back to their post. This is nothing new.
The graphics are definitely lacking. The developers clearly didn't take much initiative in harnessing the 360's capabilities and it looks more akin to the original Xbox than a next gen title. Sound could have also been implemented better, though I really didn't mind at all that all the dialoge was in Japanese, and if it wasn't I would hope there would be a way to switch it to such. I don't want to hear Ninjas in feudal Japan speaking English. The problem mostly arises in the lack of variety in victim's voices, as most of them sound the same. On the positive side I found the music to be just right. There's no swelling, surging scores or epicness here, save for the intro. It's all very subdued, traditional Min'yo and tends to set the mood for stalking very well.
Overall, if you have patience and you feel like slipping into the role of a ninja as a STEALTH... ASSASSIN... key words that people seem to be forgetting about with this game.... with light role-playing elements then give it a shot. If you're looking for fast-paced-mega-super-ultra-blockbuster-shiny action then avoid at all costs.