I learned about the Greens while listening to Radiolab, one of my favorite podcasts. Ryan and Amy — husband and wife, dad and mom — were told by doctors that Joel, their 1-year-old, had terminal cancer. And then they made an unusual decision: Turn their journey with Joel and cancer into a video game.

They named it “That Dragon, Cancer.” In a brief clip of the game, I watched and listened to the frustration of a father trying to calm a sick child. Because I am a parent, the clip took me back to those long-ago days when our son was little.

The memories were faint, in all honesty, but the feelings of frustration and fear were very familiar. My child was crying. What could I do to help him? To easy his suffering? To let him know everything would be all right?

Watching the pixelated father brought back that anxiety. Hearing the digitized cries of the baby resurrected that ache.

It was not a pleasant experience. But it was riveting, and I watched it to the very end.

Ryan doesn’t dispute that it was cathartic for him, as a game designer, to use his art to process his son’s diagnosis and death.

“To me, this is more than a video game,” he said in the trailer for “Thank You For Playing,” a documentary about the Greens’ experience. “It’s a means to talk about my son.”

Amy seems to share that sentiment.

“We’d love for the game to impact people and for it to be commercially successful,” she told Wired magazine.  “But there’s a piece of me that says, maybe it’s just for us.”

But what about the rest of the gamers out there? Is a game about a child dying of cancer and the experiences of his parents going to appeal to them?

So far, it seems so. “That Dragon, Cancer” is not only the subject of a documentary and major article in Wired, it has been written about in the Wall Street Journal and the New York Times. It has gotten rave reviews from industry experts, such as Jenn Frank.

“This is a game about something that is only inevitably coming,” Frank wrote. “But it’s coming for all of us. And that is the loveliest thing about ‘That Dragon, Cancer’: we will all meet this thing, or have already met it. Maybe that should be scary, but ‘That Dragon, Cancer’ is about sustaining the hope and joy of life for just as long as we can.”

I’m not a gamer, but I understand (I think) what “That Dragon, Cancer” has accomplished. It’s managed to gamify dying, grief and faith in a way that is unique, drawing not on fantasy characters and concepts but real people and life and death issues.

Ryan and Amy Green are Christians. Every story about them, little Joel and their game makes it clear that “That Dragon, Cancer” is very much a reflection of their faith in and struggle with God.

“’That Dragon, Cancer’ is a video game composed of pain and hope,” Amy wrote several years ago in her blog. “It is a story of my son. It is a script written day by day. It is life that moves us space by space, propelled by a mystery we call grace.”