Ooooh I like the idea of the roguelike train-builder!
It's a fun spin on the roguelike mechanics, and nice that you added interactibility while the train is on the loop to fight off the enemies. One small piece of feedback is that at the start I didn't actually realise I could shoot them, so just needs a small tooltip to let the player know they can fight them off!
We're also big roguelike fans, and built a deckbuilder for our jam game. Would love your feedback if you want more choose 1-of-3 things fun!