Testing has shown that children who play Frog's Princess exert themselves to read ahead of the voiced dialogue, improving their reading skill and vocabulary. They are highly engaged with the story, and some are intrigued by its ethical elements.
Conference paper
An academic paper about making a game with strong ethical elements was published in the Proceedings of the 2018 Annual Symposium on Computer-Human Interaction in Play.
Here is the article itself.
And here is a link to the article in the ACM digital library. dl.acm.org/doi/abs/10.1145/3270316.3270595
And here is a link to the article in the ACM digital library. dl.acm.org/doi/abs/10.1145/3270316.3270595
Teaching materials
Teaching materials can be found on the Joy Everafter website