This game does everything right, but story could've benefited from a little improvement.
The multiplayer is a whole different world. So far, I spent over 60 hours playing all kinds of online modes. There is a simple bodycount mode, which is a very good place for new players. There is also another mode which asks for random objectives such as killing/protecting the market person, capturing the battery (aka flag), capturing objectives, etc. One of the major reasons why I spent so much time playing this game is the general feel of the game. The guns feel heavy, the bullets sound real, and brutal attacks look and feel painful. It is a thriller to score that melee kill, delivering an objective, or setting your turret bot in a place that keeps giving you XP points almost constantly.
This game may not feel as snappy or quick like COD or MW, but the sense of realism to Killzone 3 very well makes up for it.
There are epic games come up only once in a lifetime, Killzone 3 is one of them.