People look at games more intently because they are actively engaged in a world through the screen with a game. A movie is just being watched, not interacted with, so the brain naturally doesn’t need or look for as much fine detail.
Like consider how closely you would look at a flower if you’re just looking at it, versus how closely you would look at it if you were trying to trim one of its petals into a little smiley face with tiny scissors. You’re going to notice more of the flower when you’re trying to engage with it. Same thing for video games.