Hey, thanks for taking the time to play my game, there's no tutorial and the mechanics are confusing so figuring them out must have taken you some time, I think the ending is broken tbh I'm not sure what happened to the collider but it just didn't work.
I'm not sure what you mean by the chance to upgrade the train because I'm fairly sure you are able to upgrade it in the safe zones or at least thats what was meant to happen. Anyway thanks for playing the game!