I like the idea, but like someone else has said, I think it is too hard to get anywhere, I did notice you tried to make it more clear what kind of parts you were working with because of the red lines and corner stones you added to the double corner tiles, but I dont think it was enough. I think the game could have benefited from some removing the time limit or having you control the train and dont let you override the pieces.
What I ended up doing was just replacing each piece until i got something useful, which is probably not intended. Maybe this could also have been solved by being able to rotate the pieces