Typically, these kinds of "devil's bargain" morality tales tend to be dark and unsatisfying, with the humans falling to the dark side invariably punished by the consequences of their wishes. The "devil" in this collection is a kind goddess, however, and her presence allows the stories to end on a hopeful note no matter what transpires.
It is by no means spectacular, but I remember that I loved its fundamental optimism despite the tragic stories within.