If you own a device with a touch screen—or know someone who does—there’s a very good chance you’ve come across Temple Run, the hit game from Imangi Studios that’s been downloaded over 170 million times. Its premise is fairly simple: Think of it like the opening scene from Raiders of the Lost Ark with more action, stretched out over an indefinite play period, and palm-sized.

Its sequel, Temple Run 2, came out yesterday and is already topping the iTunes charts. Contrary to what you might expect though, it didn’t take a huge company full of computer nerds to make: Temple Run is the brainchild of married couple Keith Shepherd and Natalia Luckyanova.

“I had always dreamed of making video games for a living—it’s the main reason I started learning programming as a kid—and we were excited about the amazing opportunity to make and distribute apps for the iPhone to a worldwide audience,” says Shepherd. “We started our business right then, and we’ve been making games ever since.”

Asked what the biggest challenge is to working with each other—besides their 7-month-old baby—they answered: “When you live together and work together at home, there’s really no such thing as work-life balance, so we found that we were working all the time, and talking about work when we weren’t supposed to be.”

Those of us in relationships that don’t involve shared office hours can probably appreciate how tough that sounds. Of course, we also haven’t made hit video games that bring in millions of dollars in revenue. Go figure!

Temple Run 2 is available now for iOS, and is coming soon to Google Play and Amazon.