In my opinion, it is perfect as is, I love the sound aspect of it, the visuals are the definition of less is more, it was a little challenging to get used to the mirror mechanic but it was very fun. Spent at least half hour on it. Highly aesthetic game.
Can see it evolve to have cool highly rhythmic electronic music, harder levels but with lives to allow for easier completion and a grading system for people that want to take the hard route and make purrfect runs, but that would make it a different game already.
Anyways, great work, loved it. :D