Ninja Assassin assaults the senses with repetitive action scenes filled with mind-numbing, computer-enhanced violence. It's scary to imagine how much worse the movie would have been had the Wachowski brothers not brought in J. Michael Straczynski to quickly rewrite the script. The film's pace is its primary problem. Lengthy flashbacks to setup the main character's motives, and interludes with EUROPOL investigators who are pursuing him don't make the plot payoffs any bigger in the end.