I noticed similarities to Beauty and the Beast as I re watched it (although I see Beauty and the Beast everywhere). It is technically an Animal Bridegroom tale, and therefore related anyway, but some alterations they made were even more like Beauty and the Beast.
In the Grimm tale, the frog asks to share the Princess' plate and bed in return for fetching the ball, to which the Princess agrees, but later has to be forced to keep her promised by her father. In this version, the frog doesn't make any requests (although I do notice now that in the Grimm he also wants to be her "companion and playfellow," which is the most this children's version hints at). This Princess, Zora, has no problem being a friend to a frog-more like Beauty than Zora's predecessors. And then the near-death of the Frog near the end? Totally like Beauty and the Beast. Also, in one of the few fairy tales that doesn't have an evil same-sex sibling to contrast the hero, they added one.
And the scene at the end? From rags (sort of) to a poofy blue ball gown and dancing with a prince? Totally Cinderella.
Yet with the insistence on keeping promises over and over, that reflects the Grimms' moral (even though Zora doesn't specifically keep a promise she had made to Ribbit). The golden ball is also unique to The Frog Prince. I must have loved this movie as a kid because my sister and I watched it over and over. Though low-budget and slightly bizarre, it was still fun to re watch.