First off I would like to say that anyone who thinks this movie sucks because it has very little plot is an idiot.
Now let me tell you what Ninja Assassin isn't.

Since the TMNT movie isn’t out yet, it’s impossible to gauge exactly how much the game has in common with it. Suffice it to say, it features all the principal characters (though seemingly none of the film’s celebrity voice talent) and touches on some of the same basic themes as the film. The whole game is told through a disjointed form of flashback narration, with the titular Turtles each chiming in at random intervals to explain some chunk of the story in the past tense (usually skipping over details that might actually make the whole thing make sense). The dialogue and voice acting is fine for what it is, but as far as providing a satisfying Turtles tale, you’re out of luck here.

Ninja Blade is an action adventure game set within modern day Tokyo. Parasites known as alpha-worms have mysteriously appeared, unleashing a wave of human destruction as they rapidly spread east, reaching the shores of Tokyo. With the future of humankind hanging in the balance, an exclusive and elite team possessing highly specialized skills is formed to eliminate the enemy onslaught, and ultimately save mankind from complete obliteration.

A westerner named Casey, studying Ninjutsu in Japan, is asked by the Sensei to return to New York to protect the legendary Yoroi Bitsu, an armored chest that contains the weapons of the last Koga Ninja.

A westerner named Casey, studying Ninjutsu in Japan, is asked by the Sensei to return to New York to protect the legendary Yoroi Bitsu, an armored chest that contains the weapons of the last Koga Ninja.

A westerner named Casey, studying Ninjutsu in Japan, is asked by the Sensei to return to New York to protect the legendary Yoroi Bitsu, an armored chest that contains the weapons of the last Koga Ninja