As a fellow train enjoyer I really liked this game ^_^
I encountered a couple of bugs, being that a wagon started going the wrong way around the loop and the counter counting 2 loops for every loop, making it go into the negatives and making the game infinite (which btw was quite enjoyable, if you patch the game after the jam I think it would be nice to see an infinite gamemode where you don't need to worry about the rounds running out and you can just play around and make a big loop).
Also after I was done with my run I messed around for a bit and found out you can still place/remove your selected thing after pressing the start loop button, so you can remove a rail on the loop when the train is running and softlock the game >_<
Great job overall! Would love to revisit the game after some polishing ^_^