Overall it kept me really interested, i was looking everywhere for the key, and given the limited color selection the art came together really well.
Now onto some critiques, i love story and narrative games and this kept me interested, although i think it may have helped to have more small details alluding towards the story. it felt as if it was attempting to be mysterious or get the player to ask questions, and i felt like you had the setup to really make this happen, but fell slightly short in keeping retention for a story.
overall i enjoyed it!