this was super good! The art, music, and platforming were all excellent.
I think the main criticism was that the gimmick was really hard to get used to, but it sure made it interesting once you figured out how it worked
specifically, I'd assumed for a long time that I was controlling the echo somehow, not that it was "echoing" my movements. (It was literally in the name, though, so I'm not sure how I missed that...) Once I figured it out, it was still kind of difficult to use, but MAN it felt cool when you used it correctly.
So far this is easily in my top 2. Excellent work.