There is definitely a market for this in the same realm as MMOs. Provide children educational problems to solve and then reward them with items that allow them to increase their ability to interact or decorate the world around them. Let the parent company guide the actual curriculum and allow kids to become creators ala Roblox to increase the number of assets available to them. They end up wanting to learn in order to get the shiny thing, and the company who puts it out gets a motivated audience.