Awesome puzzle game! There's so much breadth to a such a simple mechanic. It was executed really well!
In the spiral level where you have to jump over the spikes, I noticed you could turn around and go backwards around the spiral and avoid all the spikes. I felt very proud of realizing that, but I don't think it was an intended solution because my character couldn't make the last turn! I think 1-block-thick turns aren't possible?