The game is almost non-stop action. Full of both realistic and very intense shootouts. However it is far from perfect.

User Rating: 8.5 | Killzone 2 PS3
The game is chalked full of non-stop and very intense shoot-outs. Their is hardly any breaks that last longer than 10 seconds before you are fighting to stay alive. The enemies have excellent AI and constantly try to outmaneuver you. The shootouts require more strategy and tactics than your typical over the top arcade FPS.
The graphics are extremely well done.

Despite a lot of positives the game has some major drawbacks that cause it to never be great. First, the environments could be far more varied as well as the missions. Only one level in the entire game is based on vehicle missions while the rest is all your standard foot missions. Most of the environments tend to be urban fighting and the landscapes can get dull.
Second, the weapons tend to be dull and kind of boring. Most of them seem to be almost identical and offer very little flavor. The weapons never feel fun like Resistance games but feel more like just a tool needed to defeat the enemies.
Finally, the enemies offer zero diversity or difference. They all look identical and have the same uniform and use the same tactics. This can get old and repetitive fast.
Lastly the game never really presents any story at all. Which can seem odd but the intense action is good enough to warrant a play through to any FPS fan.
Finally the last boss Radec can be sheer frustration and took me a couple of hours to overcome. So expect some sure Hell when you approach the final boss. You will have to deal with waves of elite troops with machine guns and later RPG's then you fight Radac alone who is very challenging in his own right.