You talked a bit about physics there - obviously '2003 was one of the first games to incorporate rag doll physics, how are physics affecting gameplay in 2007?

Mark Rein: Nicely, nicely. We've started to use physics for a lot more of the effects than we have in the past, like if you noticed in Onslaught the power core has pieces falling off it. It just makes in more immersive and more believable that these pieces are flying properly and colliding with each other, things like that. We have some physics-based particle effects, the Dark Walker uses physics to navigate, the vehicles now have lots of articulations and suspension. The characters if you look really carefully - we don't just do rag doll anymore, we actually mix; we blend animation, rag doll and physics together to produce some really, really cool animation effects.

The maps are looking gorgeous as well. Will any familiar locales be coming back?

Mark Rein: Yeah, I don't know which ones for sure; I'm not really up on what classic maps we're bringing back, but the maps are just beautiful. One thing we did learn with UT2004 was to build the map as a shell first, make sure that we get all the playability correct, make sure that it's really a fun map to play before we start decorating it. In the past you would do those things together but you weren't dealing with such a high degree of decoration, static meshes and things going on in the maps that it was a big deal if you had to bust a hole in the wall. But now that's a big deal; it's so much easier to wire up a house when it's in its frame than it is once the dry-wall's in. We definitely learned a lot about how to make better gameplay by better level design.