I'm currently stuck at level 8. I do find the solution for it... I tried at least 10 times, but I hope - and will ! - find the way to level 9 :)
Edit: made a small video using the ZX Spectrum port. Enjoy :)https://peertube.pcservice46.fr/videos/embed/160ec4f5-8acf-4539-be53-ee24dbbb1fba
Thanks for the video. Regarding the challenges, if you get stuck on one, it might be a good idea to take a break and come back to it later. Sometimes, after a short break, the solution becomes clearer.