I'm not surprised; the Console (original, of course) version played pretty smoothly, but the game felt lke it could've used another month or two. The most of it was pretty solid and well done, but some bits were tacked on seemingly at the last minute and didn't fit in all that well. On the otherhand you got to pick up cars, run up the side of a building with them and then throw them at helicopters. That is, after you got bored of harpooning them with your arm and drop kicking them out of the fucking sky.
The protagonist feels a bit weak, but the big plot twist explains it all and works fairly well, except that it's a bit poorly executed in the game.
It does do the whole feeling of being in the middle of two forces fighting each other, first to exterminate the 'evil' virus and then for the good (humans) to survive. Both factions are fare more concerned with fighting each other (and/or not dying) to really be concerned with fighting you, and anything 'large' that happens is about the military fighting the infection and eventually, with the virus attack the military. The virus, starting out as a sort of zombie infection that just spreads, later gains it's own sort of intelligence and organisation.
it's definitely got a lot of make your own fun to it, but the fun you make for yourself can be quite satisfying. It's a bit difficult early in the game when you don't have ranged attacks (other than throwing stuff, or picking up guns) but you can buy a sort of extendo-arm grappling hook that lets you grappling hook to buildings and people and helicopters and pull towards them or pull them towards you, which is geneally fun, especially with helicopters.
The absorb people/identity stealing/story revealing mechanic was pretty good; if you impersonated a military person you had access to a radio and the ability to call in some form of CAS, using the codes you'd taken out of the local officer's head. There were also random dudes who had slices of backstory in their head. If they were static, and easier to find it would've been perfect, but they're randomly generated and can disappear as soon as they appear.
Plot twist for those that care:
[spoiler:bb33fb3f77]The ultimate twist is that you aren't Alex Mercer, protagonist, but slightly different strain of the virus attack the city that has become sentient, and is coming to grips to with it's own sentience whilst exploring the memories of Alex Mercer, deceased.[/spoiler:bb33fb3f77]