I just want to say, I've played plenty of puzzle games, like The Talos Principle, Snakebird, The Adventures of Lolo trilogy, Braid, The Witness, etc, and this is pretty close to those games in terms of design, challenge and ideas. I've been playing on and off for the last 4 days and I just beat all the levels, it's inmensely satisfying. If I were to improve anything, it would be adding more tunes, because listening to the same theme on a level you've been stuck on for the last hour can be slightly maddening lol. Seriously, this is really, really good and it's free to boot. I'm looking forward to your future projects.