Documentary follows a dad's inspired video game for his son

Video-game movies aren't always successful, though this one will definitely and undoubtedly reach one's heart.

Directed by David Osit and Malika Zouhali-Worrall, the documentary Thank You for Playing (in theaters Friday in New York, Los Angeles and San Francisco before expanding nationally) chronicles the story of video-game programmer Ryan Green. His 1-year-old son Joel is diagnosed with terminal cancer, and Green deals with the situation, his emotions and love for his child by spending the next two years creating the acclaimed game That Dragon, Cancer.

This exclusive scene features a show where other gamers first get a chance to play the immersive adventure and, not surprisingly, are overcome with emotion. "One of the first things people ask me is, 'Well, isn't it kind of strange showing a game about terminal cancer to this environment?' " Green says. "Why is that so strange? Why are we all walking around anonymous not talking about the things that shape the way we are?"