With over four million units of the Stronghold series sold, the hardcore historic castle building RTS from Firefly has an awful lot of fans. And now the studio is back with Stronghold Crusader Extreme and a brand new PC and Xbox 360 action game called Dungeon Hero. We donned our chain mail and sharpened our spears as we marched along to Firefly's Clapham HQ for a chat with co-founder Simon Bradbury. To arms!

VideoGamer.com: We'll start with Extreme. You've mentioned you will get onto doing a proper sequel when the time comes. Is Extreme the result of fan demand?

Simon Bradbury: Yes. We've had a lot of people asking us for Crusader 2 but we're not quite ready to deliver on it yet. We love Crusader. I like playing that game myself a lot, it's my favourite one of the series. But we're not quite really there for it yet. But there's a lot of people who wanted more so really we are giving them more. And we wanted to give them something that was more hardcore for them. Something that was a continuation rather than just more of the same, just trying to think of fiendish ways to make it even harder for them. It needed to be justifiably harder, with this new kind of gameplay twist.

VideoGamer.com: So Extreme is for the fans.

SB: It is for the fans definitely. If you're a Crusader fan you'll love it. There's a lot of new gameplay there for you. Obviously we're in the business of making Stronghold so it also keeps Stronghold in the public eye and hopefully it attracts, because it comes with the original Crusader as well, we're hoping it will attract some new people into the series.

VideoGamer.com: You've said you'll get round to doing this proper sequel when you're ready, and you've lots of fans who want to know when that might be. Any hints?

SB: Certainly we'll be looking at Dungeon Hero first, which will be out in Spring of next year, ish, and I would think if we were to start off work in earnest on Stronghold, the next iteration, it would be after that. So, that's as much as I know!

VideoGamer.com: What about a third Stronghold game?

SB: It would probably be a third Stronghold game and a second full Crusader game, is what we would be looking at.

VideoGamer.com: You would be working on it simultaneously?

SB: I'm already going to get told off by my partner for even saying this much! I couldn't tell you beyond that.

VideoGamer.com: OK. You mentioned the series has sold four million copies in its entirety. When you first started had you any idea it would be so successful?

SB: No. Well, we always believed in it as a title because we had seen that castle building games in the previous decade had sold well. And we knew there was a niche there and if we could go in with our skills, produce a good castle building game, we would do quite well. We were surprised for the demand for a castle building game both in this country and also in Germany, where when Stronghold came out in 2001 we were the second best-selling title that year all formats, which is no mean feat. This is Germany, which is a huge PC market, certainly was in 2001. We were being put out at the same time as Grand Theft Auto and we outsold GTA in Germany that year. We remind Take Two about that at every possible occasion.

VideoGamer.com: So it was somewhat of a surprise but you knew you had something.

SB: We knew it was a good game and we knew it was a good market, we were just surprised by how well it did.

VideoGamer.com: Now, in the age of the modern RTS, and amazing graphically powerful RTS games, Stronghold is still relevant?

SB: I think so. What that allows us to do, using the original engine, is put on screen far more units than anything from Starcraft or 3D work will be able to do. We know that from having made Stronghold 2, which is a 3D game. You are immediately under constraint. The engine allows us that gameplay whereas right now it would be a canny developer that could pump that number of units on screen. Definitely for that game it's relevant. I quite like the fact that it's still 2D and quite fresh really, because everything is 3D, everything is high production values, on occasion to the exclusion of the actual content in places. This really is content. We're not being led down paths by the graphics. It's just really the content we're focused on.

VideoGamer.com: Is that an approach you will keep for the series or will you ever go back to 3D fancy graphics?

SB: Stronghold 2 was 3D fancy graphics. That is where we're going with it. But we have to look at ways to in the future, it needs to look good in certain areas we're thinking and in other areas we need to get the number of units. So we are mindful of these dynamics. It's where do you save in the graphics budget and where do you try to keep it light are the kind of conversations we're having right now.

VideoGamer.com: Given your expertise of the genre, what are modern RTS games doing wrong and what are they doing well?

SB: Visually a lot of the big RTS games are really holding their own there. Story wise they are there in various forms, whether you like the cheesiness of Command & Conquer, I kind of do, because I have a soft spot for the original. You know Starcraft will have a fantastic storyline. Warcraft, fantastic. Company of Heroes. Fantastic. When you play an RTS, if it's done well it really pulls you in and gives you a lot of value in the game. Possibly if they're not careful a lot of RTS' then go too far down that route to the exclusion of innovation. Like Command & Conquer again, it was a great game, the latest iteration, but what made it good actually was the fact that it was very similar to the original and not trying to innovate too much. But that is their weak spot, it needs to kept fairly simple. It is hard to really take it anywhere.

VideoGamer.com: Is that just the nature of the genre?

SB: I think so. I know it's ours but where we've done quite well is that we've mixed genres in a way. We've taken the RTS genre and we do that but we've also got that building side, where you can place down a couple of farms, a granary and all of a sudden you've got a little world going on. A lot of RTS' have moved away from the resource side quite a lot to focus on the combat, whereas we've pushed the resource side quite heavily, which gives us a slightly different feel. We're not in that same basket with Warcraft, Command & Conquer. We're in almost a slightly different place. We're a kind of RTS, builder cross, which has done well for us actually, being a bit of a hybrid.

VideoGamer.com: Are you a fan of the Starcraft series?

SB: Yeah. I was a big fan of the original. I'm not quite Korean level but I played that right the way through all three species.

VideoGamer.com: How do you think Starcraft 2 is shaping up from what you've seen?

SB: It looks great. I'm hoping it's going to be pretty much the same game but just with high production values, which is kind of sad in a way. But I'd love them to do Age of Empires one, the same thing pretty much just better production values and a bit more immersive. I would happily go back and replay it. There's some games like Dungeon Keeper or Diablo 1 and 2 or Magic Carpet I keep getting a hankering for some reason. And you want to go back and play it. If you can play the same kind of thing but it's just a bit more woo! There's not too much wrong with that. It's tricky. If you go to a different place it's almost not an RTS anymore, you're an RTS hybrid, which is a good thing. The one I quite like, Rise of Nations, which is not a true pure RTS but it's got more to it and it's about building things and levelling up, it's kind of like Civilisation. I like that, and I think that's the way the RTS genre should go and evolve, and add more strategy and depth to it, to my mind but keep the old classics in a way a bit like a lot of the first-person stuff, just keep trundling them out.

That's all for part one. Check back tomorrow for Simon's thoughts on PC and Xbox 360 title Dungeon Hero and his view on the so called dying PC gaming market. For now, be sure to check out our preview of Stronghold Crusader Extreme.