The last version has a bug that makes it impossible to beat the game. The four digit code for the door is absent from the note, and the code from the previous versions isn't the correct code anymore.
I ran into this bug when I played it tonight. Not sure what causes it, or if it happens every time, but changing the language to Korean before checking the note in the room with the beeping monitors will let you see the 4 digit code needed to finish the last puzzle.
