Don't listen to them! 
These snacks know nothing of aesthetics.
This is a very well designed series of puzzles. They are also maddeningly difficult. The number of times I though "This level in just impossible" was far above any game I have ever played before. I'm still fairly certain Level 13 is impossible. I couldn't figure out 9 either, but 13 is just too simple for me to see any viable approach. A walk-through video would be helpful / upsetting.
Using the main game controls on the menus is always an interesting idea but I have never seen a level select menu that is a puzzle itself.
While well designed and executed, this was one of the most difficult puzzle games I have ever played. I believe the problem is in it's apparent complexity. Some of the early levels, I could get a mental picture of the level in my head easily enough and really plan out a solution. Getting more complex than that forces you to solve the puzzle as you go since fully planning an approach is almost impossible. In many games, this leads to a trial and error approach. Luckily for you, this game is way too tough for that to work, but I am still left with a complex puzzle I cannot fully internalize. Even after spending half an hour on it and going back twice, I still cannot fully remember every part of Level 9.
I'm not sure how you could improve this or even if it's something you would want to do, but just know that I have given up and am leaving 9 and 13 unsolved.
Also, I think the one way platforms need to be thicker. I had a hard time noticing them when I was trying to plan out a solution to the level. Everything else in the game is very clear.
I really liked the game, and spent far longer playing it than I intended to. (about 3 hours) I have no idea how you got through play testing within the 48 hour window, but good job for that alone.