This is so cool! I love out of bounds stuff like this and I think this is the first time someone has done it to one of my games! I didn't even know you could reach these places.
I had some plans for alternate endings that I scrapped for time, and one did involve the pool pit. The indent on the wall was always just for decoration. There was a waterfall in there originally, but I liked it better without.
I would like to expand on it some day, but I currently don't have any plans for it. Thanks for playing and I really enjoyed these OOB screenshots!