I propose new levels!!

[elexunix]

Hello!!

Really enjoyed your project, it compiled on my Ubuntu in docker without any issues, and even though I don't know Rust, the code was easy to follow to tune colors/opacity etc, and, most importantly, levels.
I understood your levels structure, it was pretty straightforward, thank you.

I propose two new, significantly more difficult levels!

I have generated them, level3.dat and level4.dat, since I found the original two levels too easy to get enough intuition in R^4 from solving them. I hope I can contribute to the project by adding the hard levels.
I attach 4d.cpp, the C++ program I wrote to generate such levels, and level3.dat, level4.dat, two labyrinths (this time real, completely not just a single path). For level 3, n=6 was used. For level 4, n=16 was used. The probability p was taken near the percolation threshold for the 4D lattice (https://en.wikipedia.org/wiki/Percolation_threshold), thus approximately 0.2.
After the generation, I have manually enlarged the blue target tesseract to make it clearly visible from the beginning.
Github doesn't allow to simply attach the files with their natural extensions (cpp, dat, dat, respectively), so I had to edit the extensions to txt to attach...
4d.txt
level3.txt
level4.txt

Hope my little contribution makes this already awesome project even better!

P.S. One minor suggestion: Maybe F/H keybinding should be swapped (at least I found it more convenient after I toggled this in the code)