The ending could have had something more to it. The posters, which I thought were going to be part of the ending, were seemingly meaningless. The first puzzle requires knowledge of cyphers, and specifically how to do the Caesar shift cipher, which seems really too much for anyone who wouldn't know what that was. Until I read a comment saying the email was a cypher, I had no idea, and then I read over it again and remembered playing a game about ciphers and assumed the minus 3 referred to the alphabetic shifting type cipher.  Also, the light powerng puzzle lacked some sort of way to tell the player they solved it; I thought the houses would light up or something would signify I could go back, but after playing with it forever I went back and assumed I solved cause of the room 2 writing. The concept is there needs work and more lore.