At Gamesblog Live, we sat down with Crytek's Nathan Camarillo, executive producer of Crysis 2. Although based in Germany, Camarillo is American. He proved fascinating on the processes involved in turning an acclaimed engine into a coherent and ambitious game, creating an urban jungle and how to use 3D as an adjunct of gameplay rather than a mere gimmick.

Crytek has always had a reputation for being at the cutting edge of games technology, but how does Crysis 2 differ from its predecessor as a game?

There has been a mentality change within Crytek. We are known for a really great engine and visuals, but we want to compete with all the best games out there, regardless of whether or not they are shooters. So with Crysis 2, we're stepping up our game in all areas to deliver at the same quality levels that we expect of ourselves on visuals.

We're really pushing not only through the tools such as sandbox, which lets us iterate really quickly on all the levels to improve the quality, but it's also about our attempts to get other content in the game and really sculpt the narrative. People who play Crysis 2 will be very pleasantly surprised by the overall increase in production quality. We've got things such as loading screen movies that are informative and tell you about the story. The 3D is amazing, and we've made a gallery that tells you all about the Nanosuit – that's all in 3D too.

In your talk, you described how even though Crysis 2 is set in a New York invaded by aliens, you've made it jungle-like, harking back to the setting of the original Crysis. How did that work?

We used a lot of the visual language that we had from Crysis. Things like rocks that you can take cover behind, jungle canopies creating dappled lighting, and natural-feeling water-flows like rivers and streams. We found a way to recreate those in an urban setting. Because it's an alien invasion, you can have the city destroyed or ravaged in some way – there's some seismic activity as well, so the streets are cracked and uneven.

So it feels more like terrain than urban asphalt. It's the same with how we tell you where you can and can't go. If we want to block off a street, sometimes there's a collapsed structure in the way; you learn which buildings you can and can't go into, because the ones you can have damaged facades. Once you're inside, they're very dishevelled and organic. So we take a city that still has the angles and hard surfaces, but simultaneously give it a more organic flow.

But you still rigorously took loads of photos around New York and modelled the city. Then, it sounds like you went and messed it up.

Yes, basically that's what we did. We made the base models, but a lot of the sets we made in the level editor started off as a rough version – let's say the clean version. Then we made a messed-up version, and when we did our art passes on the levels, we raised the quality of those assets. Thankfully, we didn't have to build the city twice – building New York once is enough for anybody.

Another key aspect of the game is the Nanosuit, which is designed to let people play the game however they want. Games have claimed to allow that in the past but few have achieved it: what's different in that respect for Crysis 2?

The Nanosuit is your way to experience the game world – your interaction with the world beyond your weapon. If you think about it, in most shoot-em-up games, you're a soldier, you have a gun and you fire at things. So your connection to the game world is the gun. But for us, the Nanosuit is in between you and the gun, even, because it allows you to interact with the world in a certain way.

We want you to feel the power of the Nanosuit in the same way that you feel the power of the weapon in a normal first-person shooter. We spent a lot of time developing that, not only through the gameplay-design features like being able to ledge-grab, slide, sprint or turn on the core powers of cloaking and armour, but it's also about the presentation of that. So, you hear your footsteps differently if you're walking, running or sprinting through the power of the Nanosuit on different material types – I can feel the suit running when I play the game. It's the same with the amount of bob on the head or the HUD – it feels like it's part of the suit that you're experiencing.

Then there's the fact that you can grab things and throw them – even the ledge grabs where you jump to get to a higher place, and you see the hands grab the ledge and interact with the world. You feel like you're in the suit interacting with the whole world. If you're cloaked and you reload your gun, there's an entirely different reload animation that happens, because you're trying to be sneaky. Then if you're in armour, it's a quicker and more violent reload, because you're probably in combat.

How does the Nanosuit work in multiplayer? There will be an associated learning curve, won't there, because the Nanosuit progression is different for the single-player and multiplayer elements of the game?

Yes. In single player, you collect nano-catalysts that the suit converts into new programs or modules that you can then activate and use. In multiplayer, based on experience, you earn tokens that you spend how you want, so you can unlock the modules you want in the order in which you want to buy them. You will probably make your decisions based on the style of play that you like. In Crysis 2, we catered more for opportunities of play-style, asking ourselves questions like: "How would a stealthy player play this space?" We played the spaces over and over based on different styles of play – we also have assassins and people who lay traps.

People find new ways to invent with this kind of sandbox gameplay. We give people a game world, but they create the game themselves when they're within the space. Likewise the artificial intelligence has to react to the decisions that you've made and the way you chose to interact with the world, so we had to have really smart systems in place that will challenge you while you're playing and force you to change your tactics. If you stealthily kill a guy, someone might notice that they're missing, call on the radio and move to your position. You still have to manage the energy of the suit like you did in Crysis, so you're only ever invisible, say, for a few seconds. So if you're going to play cat and mouse, you'll have to constantly hide, then pounce on people.

And you can get a module which shows bullet trails for when you're being sniped, offering a counter-balance to that gameplay style?

Yes, there are a lot of counter balances, especially in the multiplayer setup. We've called them classes – you're effectively picking which class you want to play. And it's a true load out: you're picking your modules and weapons, plus weapon attachments. Because people have their own styles, there is no right way to play the game. People will counteract what you're doing, then it's up to you to change.

Few developers have the courage and ambition to make a sandbox-style shooter. Does it become easier, the more iterations you make?

No it doesn't. You start to see other games taking on sandbox gameplay, so you not only want to stay ahead of those people, but you want to invent new opportunities for players to interact with the game world. Coming up with those is difficult, and because everything in our game world interacts with everything else, you always run into the problem that when you introduce something, it breaks something else.

You said Crysis 2 has been designed from the start to work in 3D, and you've kept the three dimensionality behind the level of the TV screen. Why is that?

We want the television to be the window into the world of Crysis. So, as you're sitting on your couch looking into the game world, you're experiencing it from there forwards. This makes it a deep 3D experience – we call it concave 3D, as it's inside the TV. It's an easier experience on your eyes than 3D that comes out of the TV, particularly if you sit too close to the TV. The visor of the Nanosuit sits just inside the screen, and then the gun sits just past that, then the hands and the rest of the world.

Can you talk us through the multiplayer modes?

We have Deathmatch, which is a classic – we call it Instant Action. Then there's Team Instant action, which is team Deathmatch. Then there's Capture The Relay (which is Capture The Flag). Then we have Crash Site, which is like King of the Hill, but what makes it a little different for us is that before the alien pod develops into the crash-site, a ship flies around the map to where it will pop up, before the action is under way, so it always causes a convergence on the map.

Then we have Assault, which is an asymmetrical mode. This is a really awesome game mode, where you have normal soldiers, without Nanosuits, who have machine-guns, versus guys in Nanosuits, but they only have pistols. It's team-based, and there are multiple locations throughout the map that the guys in Nanosuits are trying to hack into. While they're sitting there using the terminal, they could be shot. And it's a one-life mode, so it gets really intense.

It probably takes people three rounds to figure out what is going on – if it's early in their experience of the Nanosuit, they might not get it. But for our players who have played a lot internally, that's kind of their graduation mode – it's really hardcore. The last mode is Extraction, where one side is trying to take canisters to an extraction point.