“I think we got lucky in a lot of ways,” says Donald Mustard, the creative director of Chair Entertainment. “That said, it did feel like we were running a thousand miles an hour, in a straight line, headed for a brick wall. We were either going to hit that wall and splat, or bust through it and be okay.”

Mustard’s talking about the creation of Infinity Blade – the App Store bestseller that took the small team at Chair just five months to build. On top of the time pressure, the studio, used to making games like Shadow Complex for the Xbox 360, also had to deal with a target device with no buttons or thumbsticks, an audience that tends to play in two-minute bursts, and a marketplace in which almost every successful title had one thing in common: a 59p price point. Oh yes, and Infinity Blade was also the first major iOS release to use Epic’s Unreal Engine 3. Luck’s one factor, certainly, but how did Chair really pull it all off?

Start bloodline

If you want to be reductive, Infinity Blade’s a clever combination of sequence-spotting rhythm action and hidden object mechanics, with a little RPG levelling thrown in. You work your way through a mysterious castle battling monsters and grabbing loot, then you buy yourself some new armour and weapons, take a sword in the stomach from the God King, and do the whole thing all over again. It’s an odd combination of ideas, but it feels entirely coherent. Its origin, however, is a little less straightforward.

“It’s actually kind of a tricky to explain,” says Mustard. “When we finished Shadow Complex in the summer of 2009, Kinect had just been announced and Sony was talking about PlayStation Move. As kind of an exercise at Chair, we were trying to figure out what our next game should be. We brainstormed all sorts of ideas, and one of the things we did talk about was, if Chair made a motion-controlled game, what would that look like? We talked kind of philosophically about how it should work, the interesting control mechanisms, and design challenges. Ultimately we came up with this idea that eventually became Infinity Blade – a sword fighting game. We had that sitting in the back of our minds as we went to work on other stuff.”

About nine months later, with iOS sales really taking off, Mustard returned to the idea. “This was around the same time that our engine team at Epic came to us and said, “Wow, we’ve been able to get UE3 running on iOS, and we could actually ship a project with this,”” he laughs. “And we thought, “Huh, we actually have the perfect game for that.” So the pieces happened separately from each other, but it sort of aligned perfectly.”

At that point, of course, there wasn’t actually much of a game. “It was pretty much written on the back of an envelope,” admits Mustard. “I might have had a paragraph somewhere on my hard-drive. The thing is though, at Chair, we’re a small enough team that when we brainstorm, we can all sit in a room and design out our games together. In our minds, when we talked about the Sword Game – which is what we called it – we already had a pretty good idea of how it was going to work: touch points, dodging and blocking. There was really only two or three weeks from thinking we should make an iOS game to having sword fights that were actually feeling pretty good.”

Parry in haste

While Chair was putting together a prototype, it was also spending the initial weeks of development trying to clarify the central idea. “We’re always focused on finding the fun as quickly as possible with our games,” explains Mustard. “We’d played lots of games with swords on our controllers, but they were all about pushing buttons. We hadn’t played a game where you were actually making these gestures yourself. One of our concerns at the time was, “I wonder if the fidelity is there. If I swing my arm, will it be able to track accurately the angle of the sword swipe?” When we realised we could do all of that on a touchscreen, it became the perfect platform. We’d have that one-to-one control, and we could give you the kind of guttural connection to the action. We’d been playing games on iOS for a while, and there were games that we liked, and there were games we felt were really trying to shoehorn console controls onto a touchscreen. I knew that, if we were going to create an iOS game, we’d design it from the ground up to take advantage of what a touchscreen can do that a control can’t. We were hardcore enough in our thinking that we actually said, “If our game can even work with a controller, we’re making the wrong game.””

For Shadow Complex, Chair’s break-out XBLA title, the team looked to the genres that it had grown up loving, crafting an elegant 2D Metroidvania at a time when most studios were churning out shooters. Mustard returned to the classics for Infinity Blade, too, taking Punch-Out!!’s approach to boxing – an approach that turns each match into a puzzle as you learn your enemy’s movements – and giving it a medieval fantasy twist.

“I mean, I have no real experience of being involved in sword battles,” admits Mustard. “But I watch loads of movies, and that’s kind of what I think works best. If you were in an actual sword fight with some big dude swinging an actual sword at your head, it’s going to be much more about defending, and about reading your opponent and looking for an opening. It’s more about strategy and seeing what they’re doing. We figured, even more fun than slashing away at an enemy, would be seeing an enemy’s sword come in, and being able to knock it away at the last second. We figured if we could do that, our game will be fun, and it will be different.”

The pain schedule

If it’s rhythm-action that provided the minute-to-minute action of Infinity Blade, it was the iPhone audience that would shape the game’s inventive structure, which sees you playing as various descendants of the game’s original hero, as you fight your way through the God King’s castle again and again. (And again, if you’re clumsy like me.)

“How do you balance an action game so a new player and an experienced player are having fun?” asks Mustard. “And how do you balance that for the way that we are currently playing games on these devices? The average play session on one of these things is probably two minutes: you’re between subway stops, or you’re waiting in line at a store, or it’s a commercial break. We realised we need a game that has meaningful progressive gameplay happening every two minutes, and then, within that, you’re accomplishing something every few seconds. So even if you only have time to do one fight, you’re getting more money, you’re levelling up, you’re moving the game forward.

“But on top of that two minute loop, we also had to find ways to make it a deeper and more meaningful experience,” he continues. “That means creating story, creating long-term goals. That was a real challenge. When I normally sit down to pace a game I know that you’re sitting down on your couch, turning on your TV, turning the lights down. I know I’ve got you for at least half an hour. That’s very different to when you’re pacing the game to work for two minutes at a time. That’s what led to our bloodline mechanic: here’s an understandable two-minute loop in a single fight. Here’s an understandable thirty-minute loop in a bloodline. And then there’s a much longer loop, which we really nailed in Infinity Blade 2, where you start to realise that you need to track down this Deathless Boss or that one. That worked really well, but we did lose a lot of sleep trying to work that out.”

With the game starting to come together, Chair added hidden object elements to encourage players to hunt out treasure as they moved through cut-scenes, and the studio also chose an art style reflective of Infinity Blade’s violent medieval world. “We’d been dreaming of doing a fantasy game for years, and we wanted something a little different,” says Mustard. “We came up with this idea of “epic isolation”. We wanted our fantasy designs to be a little more grounded in science, too, or at least pseudo-science. A lot of fantasy seems to be about drawing anything you can come up with, and then that can be magic. We needed to design what our magic was going to look like, and what the rules of our universe would be. I don’t want to give too much away, because we have more plans for revealing stuff in this universe, but we have a pretty good idea of the rules of our world, where these creatures come from, and why they’re there. Because we kind of designed that early on, it informed a lot of our style.

“We also wanted this to show in our architecture. We’ve really written a lot of the history of this planet, so that when there’s a castle you see, we’ve tried to layer in lots of history to that. Look at the castle in Infinity Blade 2, it’s built on an old dam, and that dam was built 20,000 years ago. Then something was built on top of the dam, and then our castle was built on top of that. Because of that, it gives us a much more unique architectural feel: it’s like you can see the layers of history. I think that all reinforces that sense of epic isolation: you’re in a world that was once far more populated than it is now, but you can see remnants of it.”

Infinite loop

Although Infinity Blade had Epic’s backing, and even managed to get itself featured in an Apple keynote, Mustard admits that, as launch day approached, he was still uncertain how Chair’s new game was going to be received. “We really had no idea,” he laughs. “It was weird. With Shadow Complex, I knew people were going to love it, and it was going to be great. But with Infinity Blade, I knew that I thought it was awesome and that people would think it was awesome, but nothing like it had ever been released, so we had nothing to go by.

“Man, when it took off, though. We launched on December 9th, and within 24 hours, you could look at the charts and see that we were number one on every charts. I couldn’t believe it. We started to get reports back and we were selling hundreds of thousands of units a day, and we were told it was the fasted grossing app of all time and all this stuff. I was just blown away by this success. We were so tired, we’d been working so hard for five months, but the minute we saw it we were like, okay, no time for Christmas! We’ve got to get back to work.”

Much like their fated heroes, then, Chair’s been caught in an enjoyable loop ever since, listening to feedback, creating updates, and releasing a sequel that extends the game’s ideas further. “It’s different from any game I’ve ever developed,” Mustard admits – lithely dodging a question regarding when we’re going to see Shadow Complex 2 – “because you can listen to what the fans want and then put it into the game really quickly. We just released an update for Infinity Blade 1 a few days ago: we’re still tweaking, still looking at bugs, and that’s out of a response to what our players want. The game’s so customised to how audiences actually play it now, and that’s not the case when it came out.”

If Infinity Blade was a victory for Chair and the Unreal Engine 3, it was also seen as something of a test case. Can the App Store support premium games? The question is still hotly debated – not least because of the market’s shift towards freemium games.

What’s Mustard’s opinion? “I’m naïve, perhaps, but I definitely believe in the “if you build it, they will come” mentality,” he says. “Just look at the math behind it: we’re approaching 400 million iOS devices that can play these sort of games. We’ll soon be passing half a billion, and that’s so much more than the number of Xboxes that are out there. There’s just a huge number of people with these devices, with these powerful gaming machines in their pockets. The market is there, and good games, good apps will rise to the top. There are lots of different business models. We’ve obviously chosen to say, “Our game’s not going to be free. It’s actually going to cost a little bit more.” That said, I don’t think people should be afraid of the free space: there’s some innovative stuff coming out of it.

“I honestly think we’re in the golden age of gaming at the moment,” he says, finally. “There are games for zero dollars that are really worth playing, and then there are these games for sixty dollars which are just incredible experiences. And there’s everything in between. It’s just an awesome time to be a gamer. Everywhere I look I have really fun games that I can play, and I love it.”