I really like how rather than only "Count Down" as in the count going down you introduced something else to fit the theming. The movement feels a bit awkward to me, maybe the go up and down keys could be closer to WASD, but once you get used to it its not that big of a problem. An undo step button would be very helpful though, in some levels I had to start from complete scratch because I did one single step incorrectly
The puzzles are really well designed and the art is really charming, love the palette