When you think of video games, first-person shooters, high-speed car maneuvering, and puzzle solving may come to mind. But one father used the interactive medium to teach an important, touching lesson: What it's like to live with a child diagnosed with terminal cancer. Profiled in The New Yorker and chronicled in the film Thank You for Playing, video game developer Ryan Green built “That Dragon, Cancer" to illustrate the devastation of his young son Joel's battle. Joel was diagnosed with terminal cancer in 2010 when he was only one year old, and finally succumbed to his illness at the age of five. "I’m not trying to create rules for people to follow when dealing with cancer, or some potentially damaging platitude," Green told The New Yorker. "This game is just a reflection of how I see the world, of my story." Green began work on the game in late 2012. The problems you confront are hauntingly real, and difficult (if impossible) to solve. In one scene, for example, the player is sitting in a quiet hospital room. Here, the rendition of a baby Joel starts crying, and you try to calm him in vain. Other times are happier, like a scene where you can push Joel in a swing at a playground. You can linger there and relish the moment, listening to the child laugh. The game is impressionistic, the character of Joel is faceless: He's your own loved one, anyone's loved one. That Dragon, Cancer isn't the first time video games have been used to portray difficult real-life experiences. Depression Quest is an award-winning, interactive fiction game created by video game developer, Zoe Quinn. It animates the experience of depression so that those without the illness can gain insight into what it's like, and those with depression can better understand that they're not alone. The game evolves depending on your level of depression, illustrating increasing feelings by sucking the color out of its virtual world, and adding glitchy music. Other games like I'm Not Drunk and Guardian Angel tackle the tough issues of DUI and alcoholism. In these games, you can see the consequences of possible actions, and learn the right way to handle difficult situations. Players can make mistakes, and grow from them, without the consequences of making those choices in real life. As for That Dragon, Cancer, it's not just a lesson in what it's like to slowly lose a loved one (and a child, at that). It's a memoriam, a window into the life of Green's son Joel. Green's powerful hope: That after playing the game, others might care about his son the way he does. The game is set to release this fall.