First off, buy it.
This has got to be, in my opinion, the best game of 2009 SO FAR. The freedom you have to explore the city is vast and will keep you running over buildings, cars, tanks, infected hives and army bases for hours.
The ingame missions are very impressive with numerous side missions, including gliding challenges, your classic mayhem kill activities, hitman style huntings, beacon collecting and lots more.
The game controls take a while to click with, with you left bumper selecting the different upgrades plus when you do, you enter a 'bullet time' stlye slow down for a few seconds to help choosing. This also happens to target an enemy allowing you to plan your moves and the combos are great (each one being an upgrade that you can buy with points earned in the game).
The combat controls will be spot on for those button bashers as well as planners, using mainly the X, Y, B buttons in combinations.
When you play the game you'll def notice the (very similar) links to other games like spidermen, hulk, assassins creed, GTA, but thats not a bad thing and you'll see why.
The graphics took a while to grow on me, the civilians look a little false like but when you're in the heat of combat/running round you realy wont notice it. Plus when you jump into an infected street, shattering the concrete all around the character it looks pretty sweet with the sonic blast effect (not to mention the MASSIVE attack moves which take out every vehicle and person you can see)
I think the only drawback in the entire game so far is the cut scenes before the mission etc, some are a tad wooden but hey, who cares about the cut scenes right!
So, to sum it up.
graphics...5/5 once you get used to them.
freedom...6/5 (no, Im not numerically dyslexic, I did put 6)
OVERALL...5 star game, its awesome.
plus, plenty of achievments if you're bothered about that sort of thing.
You won't regret buying this game. Have fun all!