[Update: We have been asked to point out that Sybo Games is the IP holder for Subway Surfers; and has such it would make the decision over issues such as spin-off games and sequels.]
Demonstrating the massive reach of free-to-play gaming and the power of regular content updates, Subway Surfers has passed the 1 billion downloads milestone.
Developed by Kiloo and Sybo Games, two small Danish developers, the endless runner/skater, which was originally released in May 2012 on App Store, is now the fourth most downloaded games in history, behind Candy Crush Saga, Fruit Ninja and Angry Birds,
"We had a good launch on iOS but it really took off on Android," recalls Kiloo's VP of Production, Jeppe Bisbjerg.
Platform breakdown is roughly 65% Android, 30% iOS, with Windows and Amazon accounting for the remainder.
"It was also really good timing in terms of the overall growth in the market for mobile games," he adds, citing the good luck that all success stories leverage.
Despite the 1 billion barrier being broken, the game's growth continues, notably in markets such as Brazil, Russia, India, China, Turkey and Indonesia.
Having intuitive, accessible and engaging gameplay and colourful characters helps greatly in this regard.
But perhaps the most surprising thing about Subway Surfers' global status is that with the exception of the Chinese Android version - published by iDreamsky - it's an English-only game, with no localised versions.
"It's a very direct game. There's not a lot of text. The visual style is everything," Bisbjerg says.
It's all healthy organic growth. We're not fans of turning games into money-making machines.Jeppe Bisbjerg
It's a similar situation in terms of how much money Kiloo has spent on marketing.
"It's all healthy organic growth," Bisbjerg reveals. "There's no user acquisition. We're not fans of turning games into money-making machines.
"We've always taken the approach that this is fair free-to-play. There are no paywalls. We give access to all the content.
"We focus on the game itself, on player retention. That's how you see how fun your game is."
And on that level, perhaps even moreso that downloads, Subway Surfers demonstrates rude health with 27 million daily active players.
Keeping it lean
Of course, the game has changed a lot during the past three years. Indeed, its look changes every three weeks or so as a new update, including new characters and hoverboards, is released.
Currently, these are themed around a world tour, which sees the Subway Surfers' action taking place in different cities and countries. Next up is Kenya.
One issue arising from this is maintaining a decent filesize.
To ensure it reaches the widest audience, Kiloo's maintains a strict sub-100MB ceiling, this being the maximum allowed for download via 3G.
As for the future, Kiloo's rocksolid indie credentials are merely reinforced by Bisbjerg's attitude towards doing the things that all the other developers who have 1 billion-downloaded games have done.
"We're not interested in spin-off games or sequels," he says.
"We're game developers. We'd rather work on different games.
"After all, we have the most popular endless runner in the world."