I was able to swim through the walls and around the locked bedroom chamber area before it was revealed, and using the passwords on the starfish and seahorse still revealed the notes. The sprites for the notes were invisible, but the magnifying glass cursor still appeared over them and let me read them.
thanks for reporting this! Yes, there is a known issue about walls just...deciding not to work. I haven't been able to replicate it, it may have something to do with the collision loading in after the game starts or something. Also, There is a way for me to get rid of the starting game screenshot, which I have done so there's no more confusion at the start haha!
