I really like the idea of making the keyboard key sequence feel like a spin that I actually slide my fingers across it; it's very creative. I got to the point that I got 100% energy. Don't worry about my keyboard though HAHAHAHA. I like the pixel art design of this. I feel like you're serious about this.
Now, I don't know if it's skill issue but I don't really get how can we make the all the gears spin. Should I guess the order of gears that I should shoot? Is the spin dependent on which part of the gear I shot? I guess a hint or visual indicator should help. Or maybe a tutorial level so I could get a grasp on how this works. It affected on how I enjoyed the game overall.
Since there's an audio in the criteria, I think the game also lacks audio feedback when shooting or when gears are turning. Maybe you could add an audio cue addressing my previous concern.
So, overall, I really did enjoy the keyboard spin mechanic, and this game can definitely be improved more further. Good job guys!