I read your review of Ninja Assassin and agree with it.

I was bored to tears by story and the action choreography wasn't inspired enough to make up for it. . . although there were some very cool moments with the ninjas sneaking out of the shadows.

I guess is not any better or worse than some of the Ninja flicks produced by Cannon Films back in the 80s. . . (my personal favorite being the outrageously violent "Revenge of the Ninja")