Though I can understand Inkwolf's fondness for this short, I can't quite bring myself to share it - but maybe that's a bloke thing. It certainly has its good points, but for me they're outweighed by its disappointing aspects.
This film dates from 1934, and for a short of that vintage it looks pretty impressive, even on my unrestored copy. Fleischer may always have been a couple of steps behind Disney technically and perhaps aesthetically, but 'Cinderella' proves it wasn't a one-horse race, and Fleischer could still pull out some classy stuff when they threw enough resources at it. But really, their forte was never the lush smoothness of Disney. Their appeal was a bit more rough and ready, and a bit more adult-oriented.
On the plus side 'Poor Cinderella' looks really good (though not amazing) for most of the time. There are a couple of scenes, mainly in the palace, that are quite applause-worthy from a technical point of view. However it's uneven, too. Some of the characters look quite different stylistically than others. The prince looks almost rotoscoped, which makes it look quite jarring when he's dancing with Betty Boop/Cinderella.
The songs - or is it just one song repeated a lot - are/is quite effective, but it's no 'Whistle While You Work'. The transformation of the mice into horses looks good, as do the horses themselves (though I wonder why Cinderella had a cage of mice, let alone lizards in the cellar), and if it doesn't approach the opulence that Disney would soon achieve, it gives it a good shot, and probably deserves a solid second place for the time.
On the down side, the film's worst problem is that apart from a few sight gags, it just does nothing with the Cinderella story apart from shoehorning Betty Boop into it. This means that with no unexpected laughs or changes to the story, it needs to be a real work of art, and frankly it just isn't quite that good. So, to me, you end up with a predictable story, and an impressive but not brilliant production, albeit with several very nice touches.
I think Fleischer went too far in trying to compete with Disney here. They were better at straight out comedy (though the later Superman shorts are an exception to that rule). There were flashes of that style in Betty's character (the scene where the fairy godmother transforms her, involves her being magically and unescessarily undressed down to her underwear, including a garter belt, which you'd certainly never have seen if Disney had made the thing).
It was a brave and probably expensive effort from Fleischer, but to me it doesn't really have Disney's perfection, or Fleischer's usual humour, so it rather falls between the cracks. It's still well worth seeing, and certainly does have a certain charm, and if you're interested in early animation history you ought to own it. To me though, it's not the sort of thing that Fleischer were best at, and its 2.5 stars here are a little hard fought.