Saw it last night. It was...pretty good. I didn't DISlike it, but it didn't bowl me over the way, say, Beauty and the Beast did thirty years ago from its very first song. I think part of what hampered it was that they were too busy trying to shoehorn in all sorts of Easter eggs to past movies (and set up the "origin story" to some aspects of said movies) that they neglected to develop aspects that might have made it a better movie. (I think its biggest drawback was that it seemed to get more rushed as the movie went on...jumping rather quickly from development to development.)
I've been reading about some early concepts that didn't make the final cut--I don't know whether this was because of executive meddling or not. For example, both King Magnifico AND Queen Amaya were supposed to be villains originally...an evil power couple. I'm not sure I would have gone that route, but there was something that was supposed to be even more intriguing...the Star was supposed to be a humanoid shapeshifter who'd have taken the form of a dashing young teenage boy, a love interest for Asha. Sort of like Neil Gaiman's Stardust, only gender-flipped. I think that might have worked better. I'm reasonably certain that this change was due to executive meddling...that the suits thought the little non-human star would be more marketable.
And I agree that the writing for King Magnifico was all over the place. In the beginning, they seemed to be setting up his past (losing his home and family to bandits) as a major motivating factor that would figure into the ending, but that ended up coming to nothing. He really did start of with the best of intentions, but the script didn't make as much of that as it could have. It was as though the execs were listening a little too hard to the "we want a REAL villain!" crowd. We could have had a strong villain, but one who was not beyond redemption--one motivated by fear instead of greed or vanity. Sort of an inverse of the "twist villain"...instead of someone we think is a good guy who ends up being the baddie all along, we could have someone who started out as a more traditional-seeming Disney villain but ended up repenting. (Without the idea of "once you start messing with dark magic, you're lost for good.")
So here's what I might have done. I'd DEFINITELY have kept in the humanoid male star...it could have been quite a nice romance, but one that developed naturally instead of being insta-love. (We haven't had any real Disney romances since the Frozen movies!)
And I'd have cut WAY down on the number of Asha's friends. Okay, we get it, they're supposed to correspond to the Seven Dwarfs, but it WAY overcrowded the field to the detriment of their character development. (There's that over-reliance on past Disney Easter eggs again.)
I'd have gone with a more timeless, classical/Broadway sound than the Lin Manuel Miranda-esque pop sounds of the score we got. Oh, it was okay, and I do love LMM and his style, but that style seems to be getting overdone, plus it dates the movies. I'd prefer something like what Marc Shaiman did with the Mary Poppins Returns score...very much in that classic Sherman Brothers style.
Finally, to get back to what I was saying about Magnifico...I'm not sure I would have gone with the evil couple angle, but perhaps if they'd played up his past tragedy and his desperate wish to keep anyone from suffering the same, it might have resonated in the finale more. Instead of the "he becomes the Magic Mirror" angle, perhaps he could have accidentally mortally wounded Amaya, or she could sacrifice herself to try to stop him...making him realize how far he's gone, that in trying to make himself too powerful to be hurt again he has brought everything he feared onto himself, and killed the one person he truly loved. But by this point the magic he's unleashed is beyond his control, so he pleads with Asha to help...and the ending plays out more or less as before, only the "we are all stars" magic manages to bring Amaya back to life for a classic example of the "Disney Death" trope. The movie ends with a humbled Magnifico working with his wife to reform his kingdom, and a strong hint that Star and Asha are going to become a couple.
I hope this doesn't turn Disney off making more musical fairy tales...they just need to adapt some of the lesser-known ones, and concentrate on telling a good story rather than giving us a bunch of references and calling it a story. I'd KILL for them to adapt The Wild Swans/The Six Swans (with elements from both Andersen's and Grimm's versions). Or East of the Sun, West of the Moon, which is a descendant of the Cupid and Psyche myth and sort of a second cousin to Beauty and the Beast. Both have strong, active heroines, strong villains, the potential for great visuals, and involve romance.