This is adorable, and a fun game concept. It's a little limited in that any mistake derails your entire plan, although that just means that levels shouldn't be much longer than level 5 is. One big pain point is the way the game counts inputs. If you treat it like a rhythm game (like it sounds like it is) you'll actually be hitting/releasing A/D as late as possible, or even later than that. You have to actually prepare your inputs beforehand. (And also, the music is or becomes desynced from the pumping/winding of the toy which appears to be the truer marker of how inputs are taken). I would recommend "cheating" here, and recording the player's input as much as half a beat later than it currently is (so, you're counting "1, 2, 3, 4!! 1, 2, 3, 4!!", change it to "1 & 2 & 3 & 4 (&)!!" and actually count the inputs on the &s after the actual beats)
If you don't do that, I might just have to make my own version instead, so I can personally tinker with the best way to take the player's inputs. This is a great little game and I would love to see more mechanics introduced, more levels created.