This was a really fun and challenging game! The concept was pretty simple, but implemented very well! The artstyle was great, the little nerve drawings were done well - unique enough and also some similar looking to slightly confuse the player! I like that you used different colors for different levels. The way that after each level the nerves were shown in the body was a great touch! The difficulty progression was also done very well, felt that it was getting more and more difficult with 5 sequences.
A couple of suggestions - I would have liked to see some sort of short trial of sorts before the first sequence came on, it felt a little sudden that after i pressed play, i was thrown in the game directly. It wasnt that difficult to understand honestly, and after doing one sequence i could figure it out, but even having one 'tutorial' would have been nice. This sort of theme would have benefited from some in-game story or background - like why is the player doing this? And that actually would have helped a lot to integrate it much more organically with the theme! The theme integration is really good, but with a little bit of context about the overarching goal of say saving the person who is upside down, it would have made a big difference! Also, I dont know whether the player's performance in the game (or how many they got right) is shown at the end? I think some sort of differing endings can also be implemented depending on how well they did in case you plan to build on this after the jam.
The music used was really good, gave a sense of urgency to the gameplay.
Overall really well done on all fronts, congrats :)