Killzone 2 is a standard shooter. I doesn't really stand out from anything else.
One thing it does have is a much smarter AI than I'm used to. The bots actually change the squatting positions on a frequent basis and they will try to overrun the player instead cowering in their respective squatting positions. The boss fights are pretty standard, although the last one is really fun.
Their is one really annoying aspect of KillZone 2. The aiming. I've played a lot of shooters, on PC and console, and I've always had at least decent aim. Not so in KZ2. The funny thing is I have better accuracy shooting from the hip than using the iron sights. The problem is that KZ2 implements a little bit of physics when using the iron sights. For instance, the missile launcher aims sways like a mattress held on end. It's not much better with smaller guns. And forget moving and shooting while using iron sights. The spray balloons like nobody's business, even if you use short bursts. My advice is to not bother with iron sights outside of the sniper rifle, which has its own challenges thanks to addition of realistic swaying.
I haven't done multiplayer yet. I will give details after I do, if no one beats me to it. :)
Multiplayer in KZ2 is pretty fun, it reminds me alot of the actual game except you cant use cover and there are classes and ribbons to unlock. Theres times were you get mortally wounded by an enemy you lay on the ground and can't do anything but if theres a medic on your team they can heal you and you get back up were you were or there a timer for about 10 seconds and after that you can just respawn.
Online modes vary a bit but all of them are pretty recognizable from most other online games the game types are bodycount which is just like deathmatch, capture and hold, Assasination, capture the speaker/flag, and destroy/defend the objective types.
The intersting thing about online is that if there's more than one game type selected for a match then during the game the objectives change while you're playing which is kinda cool.
As for the actual game lethal has it right for the most part. i'm playing through on Elite right now which is the hardest difficulty and unfortunalty it takes away your crosshairs so your kind forced to use the iron sights or just fire blindly at your enemies which sometimes works if you know where your crosshairs should be.
I'm intrested in seeing how this game comes out, from the videos and trailers i think that im gonna pick it up when it comes out.