Seems I still haven't learned to build a minimal prototype.
I could have tested my concept on paper or with a simple no / low-fidelity GUI prototype. Instead - with me coming back to Godot after eight years - I spent way too much time on physics and input handling. I had a navigation system in mind that would feel just right. After 48 hours with two of my main mechanics coming together I realized: My idea doesn't work. Or at least, that I my idea depends on additional mechanics, with not enough time left to add them.
This is the first learning: Do a quick prototype. To be honest, this is not the first time I'm learning this lesson, but every Ludum Dare I get the feeling that there is not enough time for prototyping.

So I decided to end this Ludum Dare early and not submit anything. A part of me wants to see how much can be done until the deadline, but I know I wouldn't be content with the result. I will try to make better use of my time and do something, that makes me happy.
I had a lot of fun brainstorming and coming back to game development, I learned some things and refreshed my memory on others. So I end this on good terms. I'll try to come back next time, and maybe even join a team!

Best of luck to the remaining participants!