The PS3 finally has it's "halo".
I won't try to get into a lot of the details you read in other reviews but if I do it's because that game pulls it off very well. That being said, the graphics in this game are easily the best I have seen on either the 360 or PS3 so far. There are moments in this game, such as when your buddy Garza is talking to his friend on one of the tiny ship transports, that you will go "wow this is in game?!". I can't even begin to tell you how many times I would stop and stare at the ground in amazement at the textures or how many times I would blow up red barrels/propane tanks just to see AND hear jaw dropping explosions. Many reviewers also leave out what your weapons might do to the environment. If you shoot a table you blow a hole through it, lob a grenade at a metal barred and the barrel bends based on how the grenade exploded near it. The attention to detail in the environments is top notch.
The physics are also top notch. It is true that your character feels more like a real person than in most First Person Shooters but when you shoot enemies or when your A.I. buddies get taken out they too act like real people. The enemies will get sent to the ground by a nade, but then they slowly and realistically get back up if the nade didn't take them out. Speaking of which I have NEVER seen so many different animations for enemies getting killed and it adds a lot to the depth and realism of the game, making each kill unique, different, and also gives you the sense of truly creating this reaction to your action, in other words, it immerses you quickly!
The sound is also something to brag about, especially if you have a 5.1 surround sound system and using a fiber optic cable. Explosions are loud but they are also modeled well in terms of how they sound close up or far away; or, if many explosions happen at the same time expect that to be way louder than just a couple going off. The guns sound real and powerful, the background noise makes you feel like you are in Saving Private Ryan (minus the WWII lingo), and even the noises of these environments like wind are pretty awesome.
One thing I don't get are the complaints about the story. I see Killzone 2 much like an action movie, you aren't buying the game for the story just like you aren't going to an action movie for the story (I hope!). That being said, I didn't think the story was all that bad. I remember all the characters quite well, there are a few parts that will elicit somewhat strong emotional responses (such as what you character does in the beginning of the game with the mirror, or at the end of the game when something CRAZY happens), and I thought the dialog was a lot like Saving Private Ryan or other war movies. Crude humor mixed in with some seriousness about the situation. Just soldiers trying to have a sense of humor to keep them less stressed about their lives being on the line every second. I definitely don't think the story detracted at all from the gameplay in fact I think it helped it out a little and is nothing Guerilla Games (the makers) should be ashamed of.
Lastly, the online multiplayer is indeed awesome. I am sure you know all about how you can level up, get new weapons and abilities, so I won't blabber on about that. However, I have to say that the Map design is EXCELLENT and it is VERY rewarding to people like me who like to kind of sneak around and break away from the group to take out the enemy where they least expect it. There's TONS of different paths, way more than you would find in COD4, and the game modes are so much more fun because of the effective level design. Online multiplayer is very addictive and I think i'll be playing it for many more months.
In the end Killzone 2 is one of the finest examples of a FPS. The single player campaign is a blast, it's not too long and not too short, and when it's over you'll want to play it at least one or two more times (although I too wish it had co-op). The multiplayer is just as fun, or perhaps more fun since you never know what to expect, and the graphics are still just as good as they are in the game and it's very rare to encounter lag even in 32 player matches. Anyone that likes shooters should buy this game or at least rent it, but be warned, once you do you may end up ruining your social life!