- Support lower speeds and actually allow the engine sound to come to a full stop. Currently it sounds kind of ridiculous when you come to a stop in traffic and the engine is still chuffing along.
- Possibly: Allow the bell to come on automatically at low speeds and turn off automatically when a certain speed is reached again. This is is similar to how an actual train engine would work (though usually the bell is for alerting pedestrians and such and there's no easy way for this to know if people are around).
- Tweak the sprite configuration of the whistle to hopefully improve its sound. The source audio is not totally ideal but I've managed to make it reasonably effective at making my children smile.