Were there any major differences between developing Killzone for the PS2 and the PSP?

You could say that. This covers the casual gamer base that might pull out their PSP when commuting or on the toilet (I know you do it!) and the guys who will quite happily play for 4 hours straight.
One thing our artists had to do was relearn working on that kind of scale. They had gotten too used to their high-detail, polygon chewing ways of Killzone 1 and needed to scale back down a bit to make it work for the camera angle, but they did a cracking job on keeping the Killzone style while making it one of the best looking PSP games out there. As for the camera angle itself, it makes the game a little more tactical as it allows the player more of an overview of the area ahead so he can plan ahead a bit more.

Where exactly does Killzone Liberation sit within the series?

I think the best way to describe it is a branch within the timeline. It is dangerous to try and stick to one giant narrative that spans through many games and stick to it religiously.
The story has to be vague and unrelated enough to invite newcomers to the series without confusing the hell out of them, while still giving the fans of the previous game something to go on. So is it a sequel? Who really cares? It’s a bloody good game.

Chapter 5 and the online patch for Killzone Liberation have been very well received. Are there any more plans to support Liberation with other patches or download content?

Currently no. The reasons are twofold.
1. With the patch and content being a free download, we risked a lot financially. Having a whole development team on free content for as many months is not cheap at all. Each day costs thousands of $ in overheads, wages and whatnot and no company can sustain that indefinitely.
2. We have a big fat PS3 game we have to work on. It is all hands on deck for this.

We’ve noticed that GG is constantly looking for new talent. Is most of the original Killzone(PS2) development team still around?

A good chunk still are. I think all of the Leads are still here as is management.

E3 is very near and the gaming world is anticipating news of Killzone PS3. What’s the vibe like at GG as you all prepare? Stressed, excited?

Bit of everything. Excitement with an underlying: “OH MY GOD WE ARE ALL GOING TO DIE!” I am sure there are a hundred developers around the globe feeling the same way right now though. Everyone wants their game to play look and sound perfectly when the public first get to see it. If you are working on an AAA Next Gen beast of a game or something for mobile phones you want to make a good impression on people. And if you have the baggage that we have we have to give it that extra little bit. Hopefully it will all go brilliantly and we’ll shut up even some of the most ardent critics.

Our readers would never forgive us if we didn’t ask, but is there anything at all that you can tell us about the next Killzone title? (even if it’s a ‘no comment’, haha)

Erm… hmmm… let me see. Well it has Online. I can’t say anything about it though. There will be a Public Beta, but not till later in the year. It will be a FPS, but I guess you figured that out by now… Phew. There really is absolutely nothing I can actually talk about. Oh well. See you at E3!