I believe your post has received ample recommendations to be better, I feel I want to highlight the things I found fun in your game. I commend:
-Your game design, was simple while also being fun; but also offered a challenge to the player.
-The level transitions you incorporated were very ingenious, I loved them.
-The idea of a think-pad to remember the code is very thoughtful too, not a lot of participants would bother with that.
-Your game felt complete.
I thoroughly enjoyed playing your game and would recommend my peers to try it out.