Learning C++ using an MMORPG with embedded learning content

Following on from earlier experiments, a second implementation of a design for a game-based virtual learning environment is described, which is then tested using groups of first year students learning C++ programming. This experiment was designed to see if an environment that has been enriched with more game elements, and is generally richer in terms of interaction and activities, will create increased levels of user engagement resulting in some elements of reuse and socialisation. Thereby helping to establish what level of embedding of that material is necessary within a game, and when incorporating learning content into a game, or designing a game for learning purpose, what works best and what is the threshold for game-play? Basically what works and what does not?