A joy to play through your gamedev journey :)
Well other than that latter half of the second to last game with all the precision platforming on tiny sloped beams that could shoot you off into space without warning at times, I am so glad you decided to not keep that as a mainstay =P
Nightmind really felt like the Anti-Hatch with the similar level structure but with you having to protect the light instead of fear it. I assume one of the reason you dropped that concept was due to it being a physical object it sometimes glitched out a bit (it even managed to launch me a bit once when I was turning around in a really cramped space.)
I was surprised to see that one of the early ones didn't even feature any verticality.