Barbara Hutcheson in School Library Journal calls the story a "lyrical tale," writing that "Kyreol's search can be understood on many levels. On one, she is a child looking for the mother who disappeared years before; on another, she is a young primitive gradually becoming aware of life in cultures apart from her own; on another, she is a girl finding her way into womanhood. All these strands are developed subtly but in depth and are woven smoothly together by analogy to the River as it winds through the story. McKillip's theme is not original, but she attunes readers so completely to the primal mind of her characters that the first contact with outside forces falls like a blow. Her language is fluent and full of memorable imagery enlivened by touches of humor." She finds the "only disappointment" in the "explanation of the 'Moon-flash' of the title," which "seriously undermines not only the empathy of readers for [the] heroine, but also the author's underlying message of respect for primitive cultures" by seeming to reduce it "to a cargo culture manipulated and perpetuated by paternalistic anthropologists." Nonetheless, she concludes that "this is excellent leisure and social studies support reading for fantasy fans."[2]
Beth and Ben Nelms in English Journal write "[t]his book is a powerhouse of ideas; questions are seen as the beginning of progress; each culture is honored for what it has meant to life on ea[r]th; the quest for answers is safer and more bearable if the traveler is not alone; the power of love overcomes tribulation; and humans have the ability to love what has been while looking forward with hope and confidence to the sometimes frightening future."[3]
The book was also reviewed by Faren Miller in Locus no. 283, August 1984, Charles de Lint in Fantasy Review v. 8, no. 1, January 1985 and Science Fiction Review v. 14, no. 1, Spring 1985, Robert Coulson in Amazing Stories v. 59, no. 2, July 1985, and Michael E. Stamm in Fantasy Review v. 8, no. 11, November 1985.[1]