Free-to-play game development is very metrics-driven. While there's no doubt that Ngmoco, the Western arm of Japanese mobile free-to-play giant DeNA, closely monitors the performance of its games in every respect, Clive Downie, the head of its Western studio organization, thinks that there's one metric that stands out above all: the "number one measure of success." It's the time players spend with the publisher's games. "Ultimately I think what DeNA understands is that time is great leveler," he says. "We only have so much of it, so the things that we choose to give it to have to be great."

Cash equals game times time

"There's always a tendency for people to think that game designers and game makers, especially in this space -- in the freemium space on mobile -- they have a propensity to just think about the cash, but that's a short-term objective," Downie says. "We want people to come back to our experiences, so they have to be great uses of time." This informs the company's entire philosophy of game development. In the testing phase for a game, "the first thing we try to get is engagement, is time," Downie says. "If we don't get time, we'll kill a game." While developers can, of course, leverage tricks that lure players back, "If you don't untap emotion, all the science in the world isn't going to make somebody come back to you," Downie argues. The company will only widely release games that perform well in tests with small audiences, he says. " We prototype a lot and we throw a lot of things out."

Big audience, incremental changes

Audience size makes being absolutely sure a game is a good fit for the audience necessary, he suggests. "We deal with a world of tens of millions of people, not hundreds of thousands of people. By that I mean the omnipresence of our devices is such that there really is an opportunity there to think about broadly appealing constructs." "If you think too diversely, you bounce off of the atmosphere of taste and opportunity size." Neither does the developer target audience segments, he says. "We don't segment our audience demographically," Downie says. "We go for people who want to engage with us." "It's about desires and needs, and it's far more psychographic than demographic." In essence, the company's current plan is to make games that provide "proven" forms of engagement that players broadly find appealing. It currently has new collectible card games based on the Transformers and Marvel IP, following in the footsteps of its wildly successful Rage of Bahamut, which has been parked at or near the top of the iOS and Android top grossing charts since its February release. "When I say systems or designs that are 'proven', they are proven in that critical aspect of people spending their time on it regularly," says Downie. "A reflection of that is in their commerciality, because there is a correlation." He describes the gameplay philosophy for his studios as "wonderfully simple conventions that have high understanding with people who are playing, but they're rewarding because for every input, there's great output." Downie also doesn't look for developers who have only an understanding of the free-to-play tricks that get players engaged. Forgetting the art of game development is "a mistake," he says. The company has specialists who understand metrics, who work in concert with developers. For game makers, he says, "It's not about 'Hey, the science of freemium, and this is what you must know.' Because there's also the art of great game making that has to come back up again. It's pretty symbiotic." What matters is a knack for creating compelling games. "As long as you've got that foundational kind of instinct, you can build learning on top of that," he says.

Evolution, not copies

"We allow our studios to come to us with ideas; they're the game makers," says Downie. "Providing the people who work for us with a set of conventions they can use, a set of tools and thought processes they can use." One thing he doesn't countenance, Downie says, is cloning. "We don't copy games. I can't say it any clearer than that," he tells Gamasutra. However, that doesn't mean the company is purely original in its productions -- which you can tell from its lineup at a glance. "We will look for the things that have been successful, and think about how we can enhance and innovate on those and evolve them," Downie allows. The company's Monster Tracker, for example, resembles Pokemon -- but its gameplay is far from a carbon copy of Nintendo's franchise. To Downie -- and thus to DeNA/Ngmoco -- it's about staying on the right side of the fine line between the familiar and the copy, the engaging and the exploitative.