Thank you for playing!
Much of the feedback I've received has regarded controls, so I've already made many changes. I've added editable hotkeys and scroll wheel navigation. I've also made it possible to rotate pieces simply by clicking them, whether or not the rotate tool is selected. In favor of that, I plan on removing the rotate tool entirely. I will also make it possible to move pieces by dragging them.
I haven't considered a "replay" option, but I have added next/previous level buttons that would allow you to go back and solve a level again if you so wished. I do plan on adding more types of pieces, but I haven't decided what they will be yet.
I appreciate the feedback!