Thank you for your thoughtful comments Roey! This was my first puzzle game and I am pleased to hear you enjoyed it. The level with the U-shaped object is the best level so far I think and I hope to implement more challenges like that.
The thing that happens in the final puzzle is something where I am still deciding if I want it to be a feature or a bug, but I totally agree that if I keep it in it should be led up to in a way that explains how it works!
Reading your comments brought a smile to my face and I would love to send the future update your way for feedback. :) I look forward to playing your game. All the best!