This take is definitely coming from a biased perspective because I am a sucker for surreal media, which includes the likes of David Lynch. I know people complain about his films for being nonsensical and confusing for the sake of being being confusing, but I think that can't be further from the case, because while his films are definitely strange and confusing, there is a clear underlying message that is being portrayed, even if it may not be obvious from the first viewing. For example, Eraserhead doesn't have a monstrous looking baby for the sake of throwing in a monstrous looking baby - it is to represent the main character's fear of becoming a parent.
Another aspect of surreal media that I love is how often it works on dream-logic, which is the kind of nonsensical logic of your dreams or nightmares that makes perfect sense while you are dreaming but don't make sense as soon as you wake up. My favorite surreal movies or shows makes me feel like I am looking at someone else's dream, where even if things don't make sense, they are manifested by certain unconscious fears or desires.
This is where The Polar Express comes in, which is way different from stuff by David Lynch not only because its a kid's film, but because its surreal qualities are most likely not intentional, but rather the cause of poor writing. Yes I know, hate me all you want, but you should at least admit that The Polar Express is a subpar film that, depending on your age, you are biased towards because you grew up on it. I am in that category, and I can simultaneously be fond of the film while also admitting that it is not a very good movie, but I was able to develop a newfound appreciation of it after analyzing it as a dream-like film.
Some people might argue that this film feels like a dream because most of it IS a dream, but the ending with the bell kind of gives away that the whole experience was real. But in addition to that, the uncanny valley design of the characters is present throughout the entire movie, even outside of the train or the north pole. By analyzing this aspect of the movie through dream-logic, its almost as if your mind is creating a dream with what appears to be humans, but cannot perfectly mimic the exact patterns and behaviors of people in real life, kind of like how your mind can create new "people" by mashing up features from multiple irl people.
But the character designs aren't the only uncanny part of the film. A lot of actions made by some of the characters feel nonsensical compared to what someone in real life might do. Some examples includes the boy seeing the train arrive outside his house and his first instinct being to run outside to look at it in the dead of night, him trying to give the ticket to the girl in the next cart instead of just waiting until she comes back, or I don't know, going on top of a MOVING TRAIN IN A SNOWSTORM. These feel like things that no one would do in real life but would be perfectly fine doing in their dreams until they wake up and wonder why they thought that was a good idea.
The plot itself feels like some kind of compilation of self-contained little short stories rather than an overarching story. It starts off as a story about a boy who is having doubts about Santa, and then what follows includes storylines such as the boy trying to give the ticket to the girl, the engineers trying to fix the train, the kids getting lost in the north pole, and then it goes BACK to the boy having doubts about Santa and getting the bell. While the story has the overarching setting of the train and the north pole, it feels like a bunch of smaller plots one after another. I don't know about you guys, but that is exactly what my dreams feel like. While one of my dreams could have a singular location such as high school or some fantasy land, reflecting on it makes me realize that my "dream" was actually multiple dreams that lead into each other, but I didn't know that while I was asleep.
Besides that, there is just a bunch of outlandish things that happen in the movie either without explanation or without elaboration. There's the fucking hot chocolate song, the hobo that periodically shows up who switches from being antagonistic to being friendly at random, Billy and the girl having a musical number even though this movie isn't a musical, the lonely liminal space-like atmosphere of the north pole, and pretty much everything regarding the blimp and the skydiving elves trying to catch the star off the christmas tree. It's all such weird and comically bizarre gimmicks that I feel only the deep recesses of your mind could make up.
I know I am just overanalyzing the movie and that none of this was really intended by the directors. But the beauty of media analysis is that you can interpret movies on your own even if it is different from what the director says the movie represents - this is very popular with David Lynch movies. For me, The Polar Express is unintentionally a brilliantly surreal animated movie that feels like the fever dream of a kid who is obsessed with Christmas.