Ninja Assassin, which is bloodier than peak hour at the abattoir, offers about 2.5 films' worth of roaring action ... played with an earnest B-movie fervor.
—Kyle Smith New York Post
...killing is this film's business...and business is good.
—Chris Nashawaty Entertainment Weekly
James McTeigue comes awfully close to making a successful, gory comedy out of the ridiculous splatterfest Ninja Assassin...
—Ryan Stewart Slant Magazine
Long on awesomely bloody action sequences, short on a memorable plot or characters.
—Ethan Alter Hollywood Reporter
Ninja Assassin opens with a scene of such unmitigated gore as to classify itself more as splatter film than action flick. As it progresses, it develops into more of the latter without ever becoming good at either genre, growing as generic and redundant as its title.
—David Thomas filmcritic.com
...a mess of choppy editing and bad CGI.
—Peter Paras E!
...numbingly gory when it isn't just plain numbing...
—Michael Phillips Chicago Tribune