I really enjoyed this! it was short but I got engrossed fast and just focused, I have almost a whole page of notes from just a 20ish-minute playthrough. I kinda guessed the final key pretty easily but I was enjoying the game so much I kept playing just to find it out in-game.
I almost wish I had had to do more to get the 3 keys but maybe I was just lucky and found them quickly. Either way, it was great, good job!