This is a documentary from 2016, but it's only relatively recently been uploaded to youtube.
This is both a more important and a less pleasant documentary than the headline description implies. It's the story of a man haunted by PTSD and digital escapism after a deadly plane crash, who turns to building a nerf arena - which then turns into a community and leads to them joining collegiate Humans vs. Zombies.
It's personal and it's raw, but ultimately it's about how much a hobby that involves in-person interaction, and physical activity, and tinkering, and intense gameplay all in one package can improve people's lives.
I was not into this documentary in the beginning, but I’m glad I gave it the benefit of the doubt because the whole third act, like the last last 25 minutes or something, is great and very inspirational.