Using the Virtual World as a Learning Tool

I know my middle schooler loves using the computer! I work at a non-profit organization called the Global Challenge Award and we are trying to see if middle school children would be interested in taking online courses that teach about sustainability, energy, and other environmental topics using a virtual reality world. This world would be 3 D world where they can create characters, play games, and interact online with other players in the game. We are thinking no more than about 2 hours per week of effort would be required. What do parents of middle schoolers think about this different way of learning?