Maybe I am misreading, but I am seeing mostly bad reviews complaining that the app can only be installed on a single device? Otherwise the game/treatment has a net positive effect?
It looks like the adult version which doesn't require a prescription has in-game purchases (Google Play subscription?), so assuming it was bought that way, it seems like it wouldn't be restricted to one device. I can see the kid version being restricted if they only sell prescriptions outside of the Play Store.
I wonder what the difference is between the adult and kid versions, just the prescription requirement maybe?