A fun game I like the concept, but the gameplay gets a little repetetive so it would be good to either have an ending condition for either a certain number of request filled or time passed or having the train stop every so often at stations to pick upgrades like maybe more grills or adding more kitchen carts for the train to make managing the increasing difficulty easier.
Another thing is that bars on the clients are bearly visible when running around so it's harder to say who the order is for than when looking at the offscreen notifications