Great idea. Fantastic execution!
My only nitpicks as others mentioned is the difficulty does seem to scale really fast in those first four levels and the die layout visual could be a little more intuitive.
Thank you for blessing us with an undo feature! Those are always a pain to implement for me. The puzzles are very clever too, especially the one with the three columns of security (I got to the end with the wrong die positioning and had to backtrack).
The artwork/theming/audio is spot on (kinda gives me DEFCON vibes).