I liked it. The last puzzle was pretty hard and it was a lot of fun figuring out the solution.
I have a bit of feedback for you.
- the sound for the power turning on is very bad and I had to turn it off. The sound should be something I WANT to hear.
- the text in the level that introduces two windmills at the same time takes up too much screen space and makes it just look wrong. I don't even think the explanations of the mechanics via text is necessary.
- please add a undo feature because when you accedently pull a piece out of the screen you have to restart the puzzle.