Cancer is something we'd like to shy away from, to speak quietly about, to ignore. It's not the stuff of video games, which are realms of fantasy and escapism. It's hard to play a game that reminds us of that terrible, cruel life outside our screens.

And yet, on a quieter part of E3's show floor, I played That Dragon, Cancer. It's not the kind of game you'd expect at E3, an event brimming with twinkling lights and distractions. Yet IndieCade tucked its booth in the far back, along with all the other small-team games that didn't have the support of game publishers.

That Dragon, Cancer is a biographical game, and the brainchild of Ryan Green. Green's son, Joel, was diagnosed with an atypical teratoid rhabdoid tumor (often called AT/RT) at the age of one. In the last three years, he has had seven different tumors, each aggressively treated by radiation, surgery or chemotherapy — all therapies rarely used on young children. Each time, doctors gave Joel only a few weeks or months to live.

But three years later, Joel continues to survive. That's why Green chose to create That Dragon, Cancer, a point-and-click adventure game that allows players a glimpse into life with a very sick child.

"It's one of those experiences where I don't know what else I would do to cope," Green said at E3. While his background lies in programming, he learned Blender just to create the art for That Dragon, Cancer, too. He also provides all the narration throughout the game. Josh Larson and Jon Hillman helped out with creating the game, too.

In the demo I played, the user controls Green, who sits in a hospital room beside a crib. You click different action points, which in turn cause Green to read different thoughts aloud. Some are smaller musings — the weird color choices of hospital rooms, the uncomfortable chair in which you are forced to spend hours. Others focus on Joel's crying.

NO. Don't hit your head on the bars Joel. Joel. Joel I know you're mad. Please stop. Please. Stop.

While Joel isn't visible in this scene, his cry is a character of its own. It is an omnipresent specter haunting Green, making him feel powerless — he can't help his son or stop his pain.

Much of the 10-minute demo leaves you desperate to soothe Joel, but after several minutes, the sense of hopelessness becomes too real.

At this point, the game provides you with one clickable option. The word "pray" hovers above Joel's hospital crib in small, white text. Upon clicking it, Green's voice calls to God. The screens fade to black, and his prayer leaves me with an inescapable knot in my stomach.

I am. empty. You are. I don't know all that You are. You are there. I want you here. I want you to calm my son. I can not. And you've brought us this far. He's still here. Not Dead. Not There. With you. Oh God, I want him here with me. Please.

Yet Green said That Dragon, Cancer is still a hopeful game. Joel is still alive, and Green and his family have gotten much more time than they imagined.

Green's goal is to share this hope through the game, which he thought was the best medium to tell the story.

"To me, this is something you can't do with film," Green said. "You can observe the action happening, but you aren't in the character's head. I hope with this game, people connect in a more personal way."

Green hopes after playing That Dragon, Cancer, people will be less afraid to talk about scary subjects like cancer, and know they aren't alone.

"Everyone at this point can relate. Even if it isn't cancer, disease, challenges to well-being are everywhere," Green said. "People just don't want to talk about it."

In the end, it was too easy to relate to the game. I couldn't avoid thinking about people in my own life who had lost the battle with cancer, and the feeling has stuck with me ever since. After recounting one of those stories to Green on the show floor, he said he has had similar conversations with many others. He recounted talking about Joel with a friend at Best Buy, and the cashier behind the counter chimed in with his own survival story: He still had a benign tumor in his brain.

"When on Earth would you find out that the guy behind the counter at the local computer store had brain cancer?" Green said. "It gives people permission to talk about it, even if it's hard."

That Dragon, Cancer is still in development. To fund it, Green and his wife Amy wrote a book, He's Not Dead Yet, written from the perspective of one of Joel's older brothers.

Images courtesy Ryan Green