(Some spoilers) I'll start by saying the animation of the movie was beautiful and is a strong reason why I enjoy Demon Slayer. However it would of done far better as episodes. They spent the entire movie screaming "Justice Senpai is a great guy huh?!" and try to get you invested in him. The problem was he was a one dimensional character that could of used more time to grown on the audience. Which leads me to my next point. His death scene was entirely too long. The emotional impact wore off around 4 minutes into his speech and I was already unattached to a guy I barely knew. His death scene and it's length keenly reminded me of the Deadpool 2 movie where I actually was glad that he finally died.
The train story itself was great and I enjoyed how it was handled. My problem is the episode after the movie. We were given an entire movie with a beginning, middle, and end, then out of no where we were given a bonus fight scene. The fight scene was great but again, I felt this would of been done better with episodes with clear cuts.
I don't regret spending the money to watch it in theaters. What I do regret is people are raving about how great this movie is when there are so many flaws.