A couple of things about the experience.
1. If you are ever given a similar situation, don't babysit! I was very pleased to have a chance to experiment with a mini lesson and the kids were much better behaved because they have a new project to work on. This was a class that will never meet again and no one was expecting me to do great things with it.
2. While everyone got up and running with this and got something done, I would say about 5 more minutes spent on showing them the controls for playback and recording would have saved a few questions later.
I should have done a real-scientific-before-and-after-control-group study to see how much they learned, but I would say engagement was through the roof! A new to me way to study form. Try it!