A really clean execution. This is a very mature product for a short amount of time. A really great execution and scope! I am far too small-brained to figure out how to solve these puzzles, though, but I am in awe of how well presented this is.
If you decide to take it further, I think it would be cool to continuously spawn carriages behind the main trolley so it feels more like a train, with the added benefit of showing the player the path.