The storyline is a perfect blend of linearity and freedom. Yes, you're going to get to the same point in the end, but you get to choose how. Are you going to rampage? Or slip through the levels unnoticed, killing only when absolutely necessary? Or a mix of the two?
The level design is amazing. and while 2012 animation looks a bit dated now, the game is still beautiful.
Definitely worth a playthrough, well worth $9.99. Only bad thing I can say is that it is disappointingly short.