My sister just released a game early access on Steam[1] called "The Counting Kingdom"[2]. It targets the U.S. core math curriculum for 6-8 year olds.

The idea is that by embedding mathematics into the core mechanics of the gameplay – instead of having it simply be a hurdle players have to get by before they get to further gaming (e.g. a popup quiz) – will allow players to consistently reinforce, grow, and retain their learning without necessarily consciously thinking about learning. It's learning through play.

I think the notion has legs, but I think it will really take a strong effort between game developers and educators alike.

[1] http://store.steampowered.com/app/302750/ [2] http://www.countingkingdomgame.com/