The problem I see with measured turns is that the quality of game play is compromised. If someone sees the clock and that's when they have to stop, they won't play as thoughtfully. They're less likely to look around at the art or appreciate the music. If they're starting to read, they're less likely to take a moment to look at the text and see if they can tell what it says.
The benefits of game play will not come to full fruition if kids' time is measured that way, and they're not learning to share.
If they only have an hour, they will take ALL of that hour, just as kids whose TV time is limited will.
It they can play as long as they want to, they might play for five or ten minutes and be done. I've seen it in Holly, I saw it for half an hour in Marty.
Yes, Kirby wanted it more. He was older and it was his game system and he could play better. And so in exchange for me keeping the other kids away while Kirby was playing as long as he wanted to, he let them play as long as they wanted to, which was never as long as he did.
photo by Will Geusz, of his pets sharing