Thanks for committing so much time to doing a playthrough. I'll be honest - I haven't watched your video properly all the way through but I did skim it and got the gist of the issues that cropped up. I've been hammering away at them since then and it might take a few days but I'll post a reply here and a devLog once I've uploaded the next alpha.
As to the question, I suppose it's pretty easy to intuit just by watching a second of footage.
When I see something's going wrong that's all I need.
I've covered the lessons learned in my devlog.
Also, I've just watched your video right through. One thing I will add later is a loading screen for level transitions, I'm still looking for an elegant approach and the time to implement it. Perhaps some placeholder text is necessary.