I love how ambient and calm the music is. It fits perfectly with the dark blue void and the bright neon visuals that the game has. The visuals are also very pleasing to look at with just the right amount of smooth lighting and sharp bright lines which makes everything look clean.
I also like how in the first two levels of the game, you let the player themselves figure out the mechanic of changing color to press the button, and to move back in time in order to allow color change. No form of hand-holding used.
The movement controls are kind of awkward to use with forward facing controls controlling a diagonally moving player. I feel like the controls would work better if the player could click on the square space they want to move to, and the cube would automatically move to that spot if it's reachable; similar to the controls of Monument Valley. If this style of movement could be implemented, this could potentially work well as a mobile game.
Since the cube has a limited amount of moves that it can rewind, perhaps you could utilize the cube's glowing trail to show the amount of spaces the player can rewind with. I feel like this kind of feature would be useful since it's hard to keep track of where my previous movement was.
There is a bug where I ended up getting stuck in the third level behind the magenta bridge. There was no way to bring the bridge back down, the game wouldn't allow me to rewind to the moment where the bridge was lifted up, and there was no way to restart the level: