Okay wow, you did a fantastic job! It felt just the right amount of tension and accomplishment with the game play. I think you have a good feel for it.
Would you consider letting players know a bit of progress feedback? The level duration feels right to me, but right now when you lose the cargo, you have to restart the whole level. I think you can easily increase the game's accessibility by just gently giving feedback on how much longer they can expect to last to complete the challenge. But this is a personal preference.
Loved every minute of the experience!