I enjoyed the game a lot! Was a really chill game, the music track and the palette added a lot to the experience, and the puzzles were fun when I figured everything out.
Outside of a bug mentioned in another comment where I was unable to return to the game after clicking at some point, one thing I noticed was that some of the slots in level 3 at times overlapped at similar speeds and covered each other at some points. It made it hard to tell what slot I was hovering over at times.
Besides that though, I really liked this game, great work!