That was great! The animated train graphic at the top and bottom of the screen are very well done, and you've managed some very good (and disturbing) effects with the Bitsy graphics, especially with your use of fade-ins. A pretty nice puzzle as well (the repeating room). A very good, creepy horror story; I'm grateful that I got to play it.
In terms of constructive criticism: the writing in the poem is a bit clunky at times; not awful at all, but not brilliant either. That said, writing a story in verse isn't easy, and I wouldn't be able to do any better. (The dialogue, on the other hand, is well-written, I have no complaints there.) Also
SPOILERS
I was expecting a bit more plot in the ending: some sort of explanation of what was going to happen with the passengers, maybe. Instead it just ended with a jumpscare. A good image, but still just a jumpscare.
Anyway, these are minor nitpicks. An appropriately disturbing game with great graphics and a very creepy set-up. I'm impressed.