RocketChicken's paranoid location-based iPhone spy game CodeRunner was inspired by both British spy flicks and, of all things, Roman ruins.

Some time ago, the company's co-founder and creative lead Jeff Macpherson was visiting the ancient artefacts in Bath, England, and purchased one of those museum headsets for an audio tour.

It was all going without incident until, suddenly, the voice in his ear told him to look down. Below was the longest continuously running aqueduct in the known world.

"Other people who didn't have the audio tour were passing by, stepping over the piping. They had no idea of the history that was there!" Macpherson said. "It was that idea: how technology made something around me more meaningful."

Trust the government with your secrets

That idea of a hidden-in-plain-sight agenda, of being in on a hugely important secret, became the seed for the iPhone hit CodeRunner.

CodeRunner focuses on the Department of Privacy, a new government division that helps citizens keep their secrets safe. As its new hire, you have to first of all find and confiscate a politician's cell phone that's gone missing in your neighbourhood. Of course, it quickly gets more complicated than that.

A location-based adventure, CodeRunner turns your current neighbourhood into a spy-ridden playground. When your government handler tells you to, say, go to the nearest bank, you have to actually walk to your local bank.

Grainy videos, covert emails, and bugged conversations are also pushed over the transom, and help you to piece together a plot that should take about four hours to play out.

Waiting for technology to catch up

The blend of real-world interaction and software-generated paranoia kept CodeRunner's developers occupied for two years, but it's questionable if the game would have worked in an earlier time.

Firstly, government technological meddling is at an all-time high, from draconian legislation like America's SOPA law to crackdowns in Arab nations. Secondly, as RocketChicken notes, the tech in mobile devices has improved to such an extent that a good, compelling real-world adventure is no longer a pipe dream.

"The iPhone is really the first device to give you an experience like this," RocketChicken's tech lead Ryan Chapman states.

"Until you had a device that could track your location, communicate with the internet at high speeds, take advantage of the camera, give audio feedback, and so on, you had nothing that had the capacity to deliver the kind of immersive, emotionally engaging experience that Jeff wanted."

Other tech made the multimedia-heavy narrative possible, too. For instance, RocketChicken uses Google to determine if you are near, say, a hospital, and adjusts the storyline as necessary to make the game playable virtually anywhere.

In some cases, the covert ops narrative actually made technological limitations easier to deal with. By way of example, RocketChicken points to one part of the storyline where you're seeing a single-colour video reportedly stolen from a cab camera.

To save on memory limitations, the developer just made the video grainy (it is, after all, from a cab), and made it look almost infrared - this meant the video would seem accurate whether you were playing during the day or at night.

Android coming, in-app purchases not

Next, RocketChicken wants to bring CodeRunner to Android devices.

"We're looking into Android, but the biggest problem we're having is the scaling issue between devices," Chapman says.

Less likely are in-app purchases, for RocketChicken feels like CodeRunner should be a standalone story. It is keen on a sequel, though, especially after the positive reception to the current game.

CodeRunner seems like an odd duck compared to the birds, aliens, and cartoon critters populating other iOS games, but Macpherson says it taps into something fantasy-based games do not.

"To us, the spy genre seemed like the obvious place to go," he says. "You don't need to imagine these zombies, monsters, or threats. Just being able to blend in so easily should be enough to scare you."

Out now on the iPhone, CodeRunner will be available on Android devices in the future.