Well after buying this today and beating it on Normal in 7 hours I will give a short review.
First off the visuals and the sound are amazing. I never experienced any slow downs even when in the later missions with bad guys all over. Also the controls are spot on, once you learn them. Once you become confortable with the controls the game just flows, you start to notice paths and where to go.
The level pathing can sometimes be a bit tricky to figure out. There are multiple routes in most stages but sometimes you are forced to go a certain path and the only way you will find it is with a few deaths. Deaths will happen a lot especially if your trying to kill all the bad guys. With your death comes a revert to a checkpoint some checkpoints are better then others, youll see what I mean.
Another small nit pick is the disarming. It requires almost an instant press of the Y button when the weapon flashes red to do it. Makes some later missions hard when you actually need a gun to kill a few guys.
But other then some bad check points, and disarming people, the game is solid. I never felt bored doing the same thing over and over because finding new paths and running and doing all the jobs is just fun and flawless. If you dont want to buy it, I would suggest to rent it at least, its sucha fresh concept that was do so well, your just missing out.