Thanks for the tips. Mike Gage mentioned your work, also. We've submitted a grant proposal for working on this project but won't hear back from the Dept of Ed until 3rd week in June. Meantime, I'm spending time on my ordinary commercial projects, so I'm not sure how much time I'll have to investigate until summer -- at which point I really hope I'm working on our game project pretty much full time for 6 months.
The proposed project includes time to attempt to create a new/modified MathObject for the worked examples. If I start on that, I'll be back to these forums a bunch.