As others have said difficulty is a problem with this one. You could make this more into a planning game instead of mostly reacting by having a kind of schedule for each direction element and make the accepted products at each terminal known it advance (for example as a queue). You'd then have to plan ahead when which item is where and so on. Rating would be possible in categories like fewest switches or maybe average distance travelled.
The sound design is well done and the graphics do their job of being informative and not distracting.