I am not going to outright peg Within the Blade as a Ninja Gaiden clone, but Ametist Studio was clearly influenced by Ryus earliest incarnations, whether they realize it or not. The thing is, thats far from a bad thing. If it had emulated Ataris E.T. travesty, this would be an entirely different discussion. However, this 2D side-scrolling adventure chose enjoyable source material while bringing some new things to the table to make it less of a Ninja Gaiden clone and more of an homage to the classic series.
source: gamezpot.com