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Feb 16, 2017

Train of Thought: A Closer Look at Lumosity’s Most Popular Game

April 24th update: Enjoy free access to our most popular game, Train of Thought. The game, which has been played half-a-billion times by 20 million people, is part of Lumosity’s cognitive Attention category and specifically challenges divided attention. Enjoy unlimited gameplay now or read more in our news section.

Within a week of launching, Train of Thought became Lumosity’s most popular game. No one could have anticipated the game’s massive success with users — in fact, Train of Thought almost never got made.

Asked about developing Train of Thought, games engineer Ethan Kennerly explained, “I was asked to make a planning game, so I made three prototypes, one of which was Train of Thought and one of which was Pet Detective. In my mind, I thought of planning as planning your day — what you’d do and in what order to finish your tasks in the most efficient time. This idea of planning errands became Pet Detective, and I was originally focused on building that game for about a month.”

Of course, Pet Detective eventually became a game, too, but not before Ethan was persuaded to give Train of Thought another go. Several Lumosity employees who had tested the original prototype were really excited about playing the game, and Ethan said that their enthusiasm inspired him to turn his attention back to making Train of Thought work.

One avid early Train of Thought player was Ethan’s deskmate, Tyler Hinman. “When I’d come in in the morning he’d be playing,” Ethan said. Tyler is also a games engineer at Lumosity, as well as a five-time winner of the American Crossword Puzzle Tournament and, according to Ethan, a Train of Thought prodigy: “He processes information very quickly, so he was able to provide a lot of feedback while he played.”

As Ethan developed Train of Thought, he’d have Tyler play new iterations and provide feedback on what he liked or disliked. Originally, Train of Thought wasn’t going to have more than eight stations, but Tyler quickly mastered the game’s advanced level. Ethan added four more stations, then another two, to try to outpace even Tyler. When Tyler mastered fourteen stations, Ethan tried to add a fifteenth station, but the route generator he’d developed crashed. “And that’s why we have fourteen stations,” Ethan said — more than enough for most Lumosity players.

“I tried to make a habit of observing people playing Train of Thought three days a week, and having people across the spectrum of competitiveness play so I could give the game broad appeal,” Ethan said. “It took lots of tuning to get it right.”

For instance, feedback from playtesters and colleagues helped Ethan figure out the right balance to strike between challenging and rewarding, so the game never gets too easy or overwhelming. He manipulated the trains’ rates of departure, so when players are doing well, the trains depart more frequently. When a player makes a mistake, the rate slows, delaying the next trains so players can get their bearings and not get discouraged.

“The game can get really challenging, so we wanted to make everything else as simple as it could be,” Ethan explained. “It’s like a cookie. A cookie has no ingredients that you don’t want, only the ingredients that you do want. So for Train of Thought, we wanted to get the game down to the essentials.”

This philosophy carried over to the game’s design, too. Ethan and the designer agreed to nix the game score and other features like checkmarks when players correctly direct a train to the station. The look of the trains and stations also became increasingly simple with each iteration, and Ethan thinks the toy-like look explains some of the game’s appeal.

“A lot of people love trains, or played with toy trains when they were kids, so I think there’s some nostalgia with the design that draws people in,” he said. “And I think people respond to this idea that they have the star role in this game. You can see the drama from even just a screenshot: red train, red station, the red train needs to go to the red station, and you’re in control of making that happen. It became this really intuitive, rewarding game.”

Train of Thought is still Lumosity’s most popular game. Trying to sum up the game’s enduring popularity, Ethan observed that the game is easy to start, not so easy to master. “Because of the fine-tuning we did with difficulty,” he said, “the game keeps you in this challenging zone. And I think people of varying skill levels can play Train of Thought and get to a personally challenging level.”

Interested in trying your hand at Train of Thought? Find Train of Thought at lumosity.com or in our iOS and Android apps. Be sure to check out the Train of Thought Insight we launched last month, as well — you’ll get actionable feedback on your gameplay.

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