Look past the parkour and you've got an old fashioned beat 'em up/hack 'n slash hybrid.
Simple breakdown:
-PS2-like textures
-Incredible animations, well crafted effects
-Many clones(also relating to graphics)
-Nice, tough bosses.
-Speedy movement makes traveling around the city quick and painless.
-The side missions remind me of Assassin's Creed. Almost too much.
-You can progress through the game on your own, OR doing side missions, or both. Attack a military base, and you can wrack up plenty of of EP without ever having to do anything restricting, aside from the storyline. Choices make this much more fun for me.
-You kill. That's it. There's no fluff here, nothing extra that you need. You just destroy destroy destroy.
-Enemies require different combinations of powers to defeat. Encountering an enemy for the first time is exhilirating and tense because you never know how to beat them.
-At its heart, this is a hack n slash beat em up game, drawing inspiration from many great games. GTA, Hulk, Spiderman, RE, and likely more.
I play with the mouse and keyboard setup. It works just fine, but you can tell this game was made to be played with a controller.
Another note, many new Nvidea (the 2xx series specifically) seem to be having issues running this game. If you have those cards, you need to hold off on this game until they patch it.
I personally run an 8800gt and I can max out everything at 1920 x 1200 and run at 40-60 fps depending on the action.