If it wasn't for the nostalgia I'd given this a 4.
Is a pity, because all the ingredients are there; great actors, a solid pitch, a massive budget...but no filling, only crust.
The concept of the plot is great; a magical wish goes wrong as it means fairy tale logic is applied to real people and our former heroine Giselle is turning to a villain! Will the almost grown Morgan be able to reach past her grumpy teen persona and find her faith in fairy tales again? Great pitch!
Only that it's not what the movie is about.
There's no gradient turn of the people, no slow realization for neither Giselle or Morgan. Everything is explained as it happens, the logic of magic made up as it shows, or at least that's what it feels like as they present the answer to a problem exactly one second after it's occurred and then take three whole minutes to actually carry out what ever they just figured out before the next one shows up.
There is no generational change; Giselle is still the heroine although she's also the villain (?) and Morgan and Robert simply become completely other characters instead of gradually turning into their fairy tale persona. Missed opportunity.
I'd have loved for this to be Morgan's and Giselles story. Have Morgan rediscover her love for magic and imagination and faith in "happily ever after" by finding her self as the heroine she didn't think she was - all while Giselle yet again find her way back to what made her want to leave her former life of imagined paths for an open world that may be full of strife and conflict, but where love and overcoming those conflicts tastes all the sweeter for it.
This was not that. This was a mess of musical numbers "for the sake of it", special effects because they can do them and focus on Amy Adam's, because she's the star.
Disappointing. But not unexpected.