Thanks a lot for the carefully thought out, extremely useful feedback! Having some generic sounds ready to go as preparation for the jam is an INCREDIBLE idea that would have given us at least a place to start and we will totally do that in the future.
As for the puzzles, they're just in the order that I thought of them as proof-of-concept for the mechanics, and being so inexperienced, I spent so much time just putting them together piece by piece that by the time we had only a measly 5 puzzles it was pretty much submission time. Definitely at least reordering them might have been worth the extra little bit of time, and certainly in an ideal world we'd also have some levels that deconstruct the puzzles we have currently and build up to them.
Thanks again for giving it such a thoughtful response and even just your time playing it!