Well, I spend my first 4 hours with it last night. It's like the ******* son of Crackdown and the lightning powers from Force Unleashed, with a bit of free running thrown in for good measure. Not exactly a bad thing.
Visually it's lovely, especially when you're underground and only have the lighting effects from your electric arms flickering illumination over the scenery. The Free Running element is a bit stutter to begin with, but after a while it becomes second nature and you can put together some very fluid movements as you hop from one rooftop to the next. Gameplay is varied and intuitive, it keeps you in the "just one more mission" mindset. The Good/Evil choices will offer some sort of re-playability, (assuming the missions are different), but however it won't last you any longer then a couple of months.
O/A it's pretty good, but not a life changer. I recommend giving the full game a try, even if you were underwhelmed by the demo.