Killzone 2 is a competent game that fits into the pack solidly, but fails to rise above it.
Killzone 2's much ballyhooed graphics don't live up to the extreme hype that built up before the game's release. They are pretty good, but not earth-shattering. The characters and enemies look superb, but the environments don't. When it comes to use of the color palette, Killzone 2 is as dull as it gets. Every area – almost every wall and every object, is either a shade of gray or a shade of brown. You will hardly ever see anything besides the insides of hallways, crumbling buildings, and crates. The game is somewhat dark and shadowy. When you combine this look with the tight, cluttered environments, you can hardly make anything out except for the immediate vicinity and nearby enemies. NPC's faces look very realistic and they have great expressions. The Hellghast enemies look great, and their glowing red eyes stand out in a very cool way from the colorless environments. The game's graphics make a great first impression, but after that, they don't have a lot of impact (although the explosions are great). Heavenly Sword, Uncharted, and Fallout 3 had my jaw dropping more often than Killzone 2.
Kilzone 2's gameplay is kind of mundane. It is not bad by any stretch. Just about everything works. The weapons feel and sound very good and that makes the action of shooting somebody in the face enjoyable. The levels are well-paced and designed so that you never get lost and you are always just a few moments away from some action. Killzone 2's weapons all feel and sound powerful, a must-have for a good shooter.
On the other hand, Killzone 2 has some minor gameplay issues that keep it from excelling. It suffers from me-too-ism and fails in its attempts to hide it. One problem area is the game's pointless cover system. This is the only cover system that I know of that is entirely first person. The cover system appears to be one of those features that the Marketing Department forced into the game because everyone else is doing it. It seems like it was added without an appreciation for what makes it work in other games. You can't quickly pop out and shoot enemies in the head without exposing yourself for long. You also can't blind fire or see if a tough enemy is rushing you. Thus, the cover system has no value above just plain crouching. Rainbow Six: Vegas switches to a third person view when you take cover. Killzone 2 would have been a better game if it had done this. Instead, it flubs the feature by staying in first person to differentiate itself from Gears of War or Rainbow Six: Vegas.
An increasingly common feature in shooters is limiting the amount of weapons that the player can carry. Other games typically let you carry two important weapons in addition to some grenades. In Call of Duty, for example, you can carry a submachine gun for nearby enemies and a sniper rifle to pick off guys far away. Killzone 2, once again, copies this feature but screws it up by pointlessly tweaking it so that it can be different. The game limits you to one good weapon instead of two. This is a bad idea, because there are only a couple of weapons versatile enough to use in most situation.. You can try carrying the shotgun or the flamethrower, but they are worthless against Hellghasts that are firing at you behind cover at a distance. You can carry a sniper rifle or a rocket launcher, but those are worthless weapons for close encounters. As a result, you will find yourself using the assault rifle for almost all of the game, unless you want to constantly pick up and put down weapons.
In one maddening scene, you have to use rockets to destroy a tank from a distance without getting killed by respawning enemies who Zerg rush you until you blow up the tank. You have to carry that rocket launcher for the tank instead of an SMG or an assault rifle, and that makes you basically helpless against the swarms of enemies that come at you. It took me forever to get past this scene for the first time. I got killed shortly thereafter, and to my chagrin, I had to replay the entire scene over again because there was no save checkpoint there. Killzone 2 has a handful of scenes where Hellghasts infinitely respawn until you cross an invisible barrier that turns off the enemy's magical clone machine. It also puts hardly any save points into the game's final and incredibly difficult chapter. These parts of the game are kind of annoying. I actually did not finish this game. The scene immediately before the final boss is so mind-bogglingly impossible that I had to give up after faililng it about 25 times.
Almost everything else in Killzone 2 is borrowed from other games. The game has regenerating health. The screen turns red when you take shots and then it starts to go gray when you are almost dead. Take cover for a few seconds and everything clears up. Objectives include the usual fare of using mounted guns to defend a strong point, clearing rooms of enemies, and planting charges to blow stuff up. There are a couple of bad levels and few great climaxes or memorable set pieces. The guns consist of the usual sniper rifle, shotgun, SMG, etc that you find in other shooters, and then a couple of decent sci-fi weapons. You find intelligence documents to earn trophies. When your stereotypical meathead space marine buddies go down, you can revive them by running up to them and pressing a button. The weapons sound great and the voice acting is good, but the dialog and AI barks are all forgettable, and so is the story. The orchestral Call-of-Duty-ish soundtrack doesn't get in the way, but it is generic as they come. Enemies range from lightly armored guys carrying submachine guns to heavily armored tank guys who have a weak spot on their back. Shooting guys with glowing red eyes stays fun just long enough to keep the 8-10 hour campaign interesting.
Being derivative is not a crime if you are good, and Killzone 2 is both derivative and at least functional. Killzone 2 barely has a story. What's there is basically worthless. Considering the lofty accolades that it has received though, I found it to be overrated and slightly disappointing. I frequently found myself thinking "This is nice, but (insert name of other game here) did it better". If you are a fan of first person shooters and you are looking to add a game to your collection, then I can recommend Killzone 2 for you. However, I would caution you to keep your expectations at a reasonable level, since Killzone 2 is not the killer app for the PS3 that Sony was hoping for.