These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Broken Base: Many fans of the original special are torn on Frosty Returns, though Nostalgia Filter seems to give it a few points for some.
Ear Worm: Frosty Returns may be flawed, but "Let There Be Snow" is somewhat catchy. Bonus points for actually being sung by John Goodman.
Fanon Discontinuity: Most fans' opinion on Frosty Returns. Not helped by the fact that it is pretty much incompatible with the other sequels that were officially made by Rankin/Bass called Frosty's Winter Wonderland and Rudolph and Frosty's Christmas in July, both of which now belong to Warner Bros. while DreamWorks Classics, formerly known as Classic Media, currently owns the rights to the original special.
"Funny Aneurysm" Moment: "Stay in here much longer, and I'll really make a splash in the world." Funny when Frosty said it upon entering the greenhouse, not so much not two minutes later; perhaps even a record-setter as far as these go.
Moment Of Awesome: So after Santa rebuilt Frosty and was about to put the hat on, Hinkle comes to grab it again. How does Santa put an end to it? By threatening to never give him any more presents for the rest of his life. It instantly shuts him up.
Possibly even earlier when he douses Karen's campfire, which was the only thing between her and freezing to death. It's especially bad because he does so for no good reason. At least killing Frosty helped him achieve his goal of getting the hat back, but endangering the little girl achieves nothing.
The worst part about Hinkle is, he wants the hat back solely because of greed, claiming he'd be "a billionaire magician" if he had it. That's kind of low.
Part of the reason the Green Aesop fails is that it the ecological implications of a world without winter are only briefly touched on. For the most part, the message is that we need to have snow because snow is fun and pretty.
Tear Jerker: When Frosty is melted, and again when Frosty and Karen have to part in the penultimate scene.