Neat little puzzle game! I like the concept. The difficulty ramps up a bit quickly, especially heading into the final level, but the game does a good job of demonstrating its mechanics, leaving players with nothing but time to figure out the last one.
Besides the obvious lack of audio, I think this game would shine with some input buffering, allowing inputs a few frames in advance to make quick moves in succession feel smoother. That was my only real pain point, though.
Great job! I’d love to see this concept further fleshed out in the future.