Oh, I see. So you're less looking at it as an intrinsic motivation - kids wanting to get good at English so that they can make things of their own - than as a way to build a task for students.

I quite like that idea. Maybe you could use them for verbal exercises that stretch those linguistic muscles - e.g. getting them to explain a complex concept in precise language to an agent that is constantly trying to poke holes in their response. Though maybe that'd just end up being frustrating!