If you watch it on its own terms, you may just enjoy yourself.

Rating: 7/10 (10 November 2017)

I'm amazed to say I LOVED IT! I truly did. It was gorgeous to look at (money was SPENT!). Going in knowing whodunnit is especially fun when there are people in the audience who audibly don't! I had a great time!
Now, I'm sure people want to know how it compares to the 1974 Lumet film with Albert Finney. And the answer is... IT DOESN'T AND IT'S RIDICULOUS THAT YOU EVEN ASK!
Honestly! That was a FILM! This â€“ and it makes no attempt to hide the fact â€“ is a MOVIE!!! It's a delicious, giant, Agatha Christie themed cake. It's the kind of movie that requires you to eat while you're watching it. So, if you see it and don't like it because "boo hoo it doesn't compare to the original," it's you're own fault you didn't enjoy it.
There are a goodly number of reasons not to enjoy this version on its own merits. But first, the good stuff!
Kenneth Branagh, director. He keeps things moving at a good clip. It survives the true test of a period piece: I wanted to buy or wear everything in it. It's not easy to make a mystery where everyone over 40 knows the ending! He approaches it with style and aplomb!
Kenneth Branagh, actor. His Poirot is surprisingly understated; shockingly so when you consider the heinous moustache (it's the kind of moustache that requires the spelling with the most letters). The anacondapillar on his face aside, there's wit, charm, subtlety and grace in his performance. It's not iconic Finney or Ustinov but it'll more than do. In fact, I found him quite moving.
Josh Gad. I am not a fan. I don't find him funny or appealing at all. Except in this because he's fabulous! The character's pathetic slovenliness is actually endearing and the period look really works for him. It's terrific work.
Leslie Odom Jr. I did not see him in Hamilton so this was my first experience. He's beyond appealing.
The very best thing about this film: Michelle F-ing Pfeiffer! Between this and mother! I'm loving how much fun she's having. She OWNS this movie!
Now the other stuff.
A lot of heavy hitters have very little to do. Dame Judi, Derek Jacobi and Olivia Coleman are only here to give the cake some class. And they do! But...
Some of the other characters are given extremely short shrift. The Count and Countess (played by Michael York and Jacqueline Bisset in the original) are played respectively by a non-actor and a relative unknown (Lucy Boynton, who was delightful in Sing Street but is no Jacqueline Bisset) and are barely in it. I'm still not sure how the one Latin guy was involved.
While the movie deserves props for at least trying to make a period murder mystery with at least a few actors of color, it would have been nice if they all actually had stuff to do. But when even Dame Judi is just collecting a paycheck...
The screenplay and some of the acting is a bit cartoony. Daisy Ridley is serviceable. Willem Dafoe is trapped in a character with no way out but DAMN if he doesn't commit to his Choices! Johnny Depp seems like he's in a different movie altogether.
There are unnecessary action sequences and the screenplay's other attempts to get you to where you're inevitably going to end up feel forced: like someone at the studio said "I think you need a car chase only without cars and on a stalled train." When people actually start confessing, I was like "don't DO that!"
The reenactment of the murder is a bit too stylish for me and takes away some of the horror of what's happening, though it does capture some of the rage.
All that said, I really did enjoy myself! If you can watch this movie version without being mired in comparisons to the previous great film (and if you properly adjust your expectations), you might have fun too.
No guarantees.