Thanks for playing! Yes we wanted to underline the importance of balancing out the cargo (I still feel it's a bit too easy to get a balanced load, but then again i spent the last 10 days playtesting that mechanic :P )
Thanks for the feedback, we'll get on that bug once the rating is done. The current of the river is something we didn't have time to exploit as much as we would have liked, but maybe that's for the best since it can make the game quite difficult as you say, and it might have ended up a bit too hard :P