When the participants in the study were tested immediately after playing the game or watching the video and then a couple of months later, everybody improved, but the game players improved more than the video watchers.
I think the effect a video game had on people's ability to learn about and overcome cognitive bias is really interesting. It sort of shows how important and influential things like movies, tv shows, games and other fictional entertainment can have on a person, perhaps because of the emotional investment attached to it.