Christopher Fujino’s review published on Letterboxd:
This was supposedly made because Miyazaki & Takahata couldn't secure the rights to Pippi Longstocking, and it's an obvious precursor to My Neighbor Totoro (right down to the title song). But the children's story I was reminded of while watching Panda! Go Panda! was The Many Adventures of Winnie the Pooh, with it's serial/anthology of shorts format, and premise of idyllic childhood autonomy in a non-threatening world. But the strength of Winnie the Pooh is how funny the characterizations of the animals are (Eeyore is depressed, Rabbit is a neurotic compulsive, Owl a know-it-all who knows nothing, et al), and characterization is sorely lacking here, especially from the supporting characters.
Postscript: the Japanese title is "Panda Ko-Panda", where "ko" means "child". I can see why they simplified this to Panda! Go Panda!, but it's another case of a Ghibli film with a nonsensical English title.
PPS: the fact that Mimiko becomes daughter and mother, without being a wife or sister is mildly interesting from a sociological perspective. I started to draw parallels between this and Ozu's Late Spring, but only because I was so bored by the dumb plot.