I don't think it quite works, which is a shame. I love Michael Caine, the Muppets and Charles Dickens. Nevertheless it's still an interesting adaptation with a ton of personality and a genuinely must-see performance from Caine.
It has two problems, of which the first is the songs. At their best, they're merely fast-forwardable. At their worst, they break the film. The Spirit of Christmas Present uses a musical number to sell Scrooge on the wonder of Christmas, for instance, but unfortunately the song's so bad that it doesn't fulfil this narrative function and instead leaves a hole in the motivation. When Scrooge starts dancing (badly), you wonder why. Similarly the big "look at us, we're happy" song at the end doesn't really convey happiness, or indeed anything except the fact that studio executives thought their movie needed some songs.
Admittedly all the Muppet movies have songs, except Muppets from Space, but that's still no excuse. Unfortunately you can't simply cut the songs out of this movie, but it's still about twenty times better as a film when it's got dialogue instead of lyrics. I liked Kermit's a capella with Tiny Tim, though.
The other problem is Michael Caine, despite the fact that I'm about to rave about his brilliance. He's having trouble with his muppet interaction, especially when the little bugger isn't even there and is instead a special effect being added in post-production. Someone needed to be clearer on eyelines, although that's the production team's fault as well as the actor's. On top of that, he's unconvincing during his song at the end. Of course none of this means he's not a titan giving a masterclass when it comes to traditional thespian skills, but he is shaky in the more specialised "Being In A Muppet Movie" requirements.
The annoying thing is that these shouldn't be movie-killers. They're relatively minor points. Unfortunately they derail key passages in the film just enough to knock it down from greatness.
Everything else I loved.
The main selling point for me was Michael Caine. My God, he's good. Even if you hate all three of the Muppets, children's films and Charles Dickens, because of him I'd still tell you to watch this film. Apparently he regards this as one of the most memorable roles of his career and if so, he's right. He's less evil than you'd expect in his early scenes as the heartless (and funny) skinflint, instead tempering the cruelty with undercurrents of vulnerability, but that just means he can start breaking your heart pretty much as soon as the ghosts get going. He had me nearly in tears. "Oh, please. Do not show me that Christmas." Caine's Scrooge isn't a villain who turns good, but a man who'd lost himself. He made me laugh with his mean-spirited miserliness, but I was never afraid of him. He also finds a slightly surprising way of underplaying "bah, humbug", which is lucky because the script makes him say it 10000000 times.
However the Muppets are cool, too. They've got Gonzo claiming to be Charles Dickens and narrating the story for us, which surprisingly provides some of the film's funniest scenes. You see, he's got a sidekick in Rizzo the rat. There are some brilliant cameos from back-up Muppets like Sam the Eagle ("It is the American way!"), the Swedish chef and Animal. Miss Piggy is wasted and should have been one of the three ghosts, but Kermit fascinates me in how a green lump of felt with no audience-pleasing eccentricities can be so charming. He's perfect as Bob Cratchit. I really and truly think there's something interesting in Muppet versions of classic films, in that this is a faithful Dickens adaptation that's being pulled in unusual but valid directions by having these clearly defined personalities in it. If anything, I think this one hasn't been Muppetted enough (e.g. not making enough use of Miss Piggy).
Also, just as importantly, they're fun. There are singing vegetables, for instance.
It's being true to Charles Dickens. For example the ghosts were going to be well-known Muppets (Miss Piggy, Gonzo and Scooter), before it was decided to play them straight. Gonzo was made the narrator in order to have him speaking us Dickens's prose word for word, while the characters are often saying dialogue that's straight from the novel. Someone here loved the original book. Like, they worshipped it. Bizarrely this might be more faithful than some straight adaptations! They're not dumbing down Dickens's vocabulary, on the contrary having Gonzo call himself "omniscient", while I was slightly surprised to see that there's no comedic interjection to undercut Caine's despair in the graveyard scene. They also don't overplay Tiny Tim.
Oh, and it looks great. Somehow the Muppets fit in Dickensian London. I love it, but I can't explain it. This film looks both beautiful and authentic when it's doing the cobbled streets and Michael Caine in the correct historical garb, yet somehow a bunch of singing Muppets seem to belong in this world too.
Overall, I want to love the film more than I do. I could be here all day listing great things about it, but those two problems I mentioned hurt it. Caine's magnificent, but struggling with the Muppets, while the songs are poor. Nevertheless I'm still very pleased I saw this. I'm serious in saying that Muppet adaptations deserve critical attention, but at the same time it's going to succeed in its main role of entertaining small children because the Muppets are funny. If nothing else, Scrooge is a brilliant character for a children's film because "I hate Christmas" is on a par with "I eat babies" and "you're not getting any birthday presents".
And, you know, Michael Caine.
"A gift? A gift for me? Thank you."