The UK OPM magazine only has the mall level; I've heard less than favourable comments about the trench level - but I've also heard its a training level as well?
I didn't notice any frame rate issues, it looks 30. But then again I didn't notice any frame rate issues witth PS2 SSX. I'm not senstive to frame rate stalls unless they are bad.
The mall level has great style and atmosphere, and thats what I loved about it. As for FPS gameplay? I don't know, it hasn't got that Halo flow, but few FPS's have, and I'm not an FPS junkie anyway. But I love it's style, and it plays well enough.
I'm not technicaly capable with FPS's, I played through Halo on easy, anything harder and I'd have never made it. But KZ is quite tactical, you have sufficient resources to stay alive as long as you don't soak up too much damage in a short space of time, but throwing grenades and reloading weapons leaves you really vulnerable.
The AI is reasonable as well, youir team fight well by themselves, they support you, and will cover for you, but give them enough time and they can clear areas by themselves. The Helghast are quite canny as well, they run forwards behind cover and give supporting fire, use secondary weapons; and fall back; they will occasionaly get confused and just stand facing the wrong way waiting to get slotted.
Controls are good, not as good as Halo (best joy pad FPS), but the control layout is Halo based, and I had no problems. There doesn't appear to be an auto aim, but I could aim and kill stuff. There's a sprint option, pressing L3, which works great you put your weapon out the way and run. Again it helps you to think tactically.
My overall impression is that KZ is a creditable FPS, wrapped in wonderfully atmospheric visuals and audio; think Ico goes to war.
Based on the Slums level I'm hoping for an Edge 7/10.