Besides the innovative style of gameplay that mirrors Edge has, it's actually quite beautiful (even on the same engine as GOW2) it's very artistic, the colors the lighting it's just so...fresh.
Also the gameplay I -love- parkour and I love how they did it in this game; even the story is amazing despite what people say. The combat in Mirrors Edge is also neat, though I haven't played the actual game, just the demo, I love it. I really, really want this game, gow 2 (just like gow) I don't really care and I will never own it. :\