[As part of a series of "Road to the IGF" interviews with 2011 IGF finalists, Leigh Alexander speaks with stfj's Zach Gage about Best Mobile Game nominee Halcyon.]

Named for a mythical Greek bird, recently released iPad title Halcyon is described by its developer as "a unique spatial action puzzler / generative musical instrument."

That's a fancy way of describing a game that involves matching up like-colored triangles to each other as they travel slowly along increasingly crowded strings, creating an elegiac soundscape as you do.

Gamasutra talked to stfj's Zach Gage about the failed concepts that led to Halcyon's creation, his favorite fellow IGF finalists, and more.

What development tools are you using to develop Halcyon?

Halcyon was written entirely in OpenFrameworks, an open source C++ library for Creative Programming.

How long have you been working on the game?

Halcyon is actually the fastest commercial title I've ever worked on. Kurt [Bieg] and I put it together in a quick two and a half months.

How did you come up with the concept?

Weirdly, Halcyon came out of a few months of thought about an entirely different type of game. As soon as I got my hands on an iPad all I wanted to do was make some kind of deep, re-playable 2-player competitive game.

I spent a long time with prototypes for sort of a "Versus Missile Command style game with some light RTS elements, and had a lot of thoughts about how a tower-defense game could be structured to have opposing players. None of it ever came together into anything fun.

What little did work was a core concept that the game had to be simple to grasp, but with so many elements happening at once that it would be impossible to keep track of them unless you were really good. That the ability for one player to be greater than the other would come from capacity to manage multiple objects, and not just strategic thinking.

Then Erik [Svedang] released Shot Shot Shoot and I discovered that he had solved exactly what I was working on and in a way far better than I had managed to. So I scrapped the idea.

Something that I found really interesting while playing Shot Shot Shoot, though, was its vague lines. Because you only have 5 bases, you at first believe that the attack portion of the game is structured into 5 columns. Of course it isn't, but the layout makes the game more approachable. This concept really stuck with me, and it formed the basis for interaction in Halcyon.

With my [competitive] game aspirations quashed, I changed my train of thought to thinking about how to make a puzzle game like my previous iPhone game, Unify, for the iPad. I spent a lot of time thinking about it with no luck and then one day in the shower the mechanic of Halcyon hit me, I wrote a prototype in a few hours, showed it to Kurt, and the rest is history.

I guess it was more of a melting pot of ideas magically coming together than an aggressively prototyped game.

Have you worked on Halcyon exclusively with Kurt, or have you brought in input from others? Does this way of working make it easier or more difficult to actualize your vision?

I worked on it entirely with Kurt. I put together the prototype for the game and some sound ideas, and then we worked together on the design of the instrument side of the game, and the levels.

I like to make very simple games that have extremely deep mechanics if you get into them. Unfortunately this means I have to get very deeply involved into playing my own games, and this makes it difficult to criticize them. I think I have a very strong curatorial sense, but that doesn't often translate well for sales.

My game design is depth first, and so sometimes it's hard for me to introduce people to that depth in an accessible way. Fortunately I'm getting better at creating strong tutorials, and Kurt comes from a game design culture of extensive play-testing so he was very helpful on that front.

Are there further things you want to do with the design, and how are you viewing that process?

I'd like to create some sort of co-op or versus mode. Actually, Halcyon has a co-op mode already, but I wasn't sure how to publicize it. Essentially you just put the iPad between yourself and a friend, and attempt to cooperatively play any level in any mode. I think aggression mode works the best, but it can be done with any mode. This may sound like a cop-out for a multiplayer, but Halcyon was actually designed for this to be possible.

The difficulty of creating a multiplayer for Halcyon is that the game isn't about competition. I prototyped a number of competitive multiplayer modes and none of them worked specifically because of this fault. This is why the co-op mode works so well.

When you attempt to play co-op with someone else, it quickly because impossible to communicate what is happening or delegate tasks. The only way to succeed is to intuitively work with the other player. Although you eventually lose, the play experience is extremely intimate and curious. This is really what Halcyon is about, bringing things together.

Aside from that, we're considering building a mode specifically targeted at children, with bring shapes and simple level design.

Are there any elements that you've experimented with that just flat out haven't worked with your vision?

Oh my god, so many. Halcyon is the most finicky game i've ever worked on. I luckily nailed the fun part in my first prototype and Kurt nailed the sound in his first as well. Thank goodness we did because after that it was failure after failure.

I think we maybe designed another dozen iterations before we got Halcyon right. From failed versus modes to level design mechanics that didn't work to sound sets that were way too new-age or abrasive, Halcyon is extremely delicately balanced. Looking back it's hard to believe how much work went into something that seems so simple to the end user.

Have you played any of the other IGF finalists? Any games you've particularly enjoyed?

Oh, totally! I've played a lot of them. Sorry for the list-style of this run down, but it's too many games to go in to depth on each!

Bit.Trip Beat is probably one of my favorite games to come out in the last 10 years. Talk about a simple mechanic pushed to it's limits.

Cave Story I've played through twice now, the original PC build as well as the Wii version. Both are totally amazing.

Nidhogg I've lost at far too many times, but its always been fun.

Desktop Dungeons is completely genius, I hope those guys come out with an iPad version soon as the Mac port runs terribly slow.

I've loved Faraway since I saw it last year at GAMMA (and I'm pretty sure I'm 3rd in the world in it).

Super Crate Box is completely addictive and amazing (and freaking tough! I heard Colin Northway is a pro at it though, I'd like to see that).

Colorbind is easily one of my favorite iPhone puzzle games, and one of the few in this list that I'd heard of before it came out and was really excited for.

Shot Shot Shoot is inspirational and really, deeply awesome. I'm excited it's at GDC, I've played it a ton and am looking for challengers.

And, of course, Solipskier. I had the highscore on this briefly (a day or so after it launched). Really awesome game. Mike and Gregg are great dudes and I'm so glad they finally made an iOS game (and a crazy successful one at that!)

What do you think of the current state of the indie scene, and how does iOS rate as an avenue for independents?

I'm very new to the indie scene so it's hard for me to judge. I didn't even really know I was a game developer until two years ago at Indiecade when I met so many awesome developers.

Personally though I feel like iOS is a really amazing platform for game development. Despite the problems with cloned games and low prices, there's a reason you don't hear so many success stories coming from any other distribution platform.

Although some times it's tough to get attention for indie games, and i definitely feel like Apple promotes too many mainstream clones, there's no audience like the iPhone audience.

Even though many users are mainstream, people from all walks of life own iPhones and I can't count the number of talented designers or musicians I've met through putting my work on the App Store. Apple should be proud that all the mobile finalists are iOS developers. They should be so proud that they should feature us (hint hint).

[Previous 2011 'Road To The IGF' interviews have covered Markus Persson's Minecraft, The Copenhagen Game Collective's B.U.T.T.O.N., Alexander Bruce's Hazard: The Journey of Life, Nicolai Troshinsky's Loop Raccord, Chris Hecker's Spy Party, Frictional Games' Amnesia, Monobanda's Bohm, Gaijin Games' BIT.TRIP.RUNNER, SpikySnail Games' Confetti Carnival, Ratloop's Helsing's Fire and QCF Design's Desktop Dungeons.]