Thank you! I'm so glad you enjoyed it! Many of the old 3D platformers were big inspirations for this.
That's a pretty funny bug! I think it probably is possible in all builds of the game. My character controller ended up becoming a giant mess, and I wouldn't be surprised if there are some other quirks you can get out of the character. Somehow there is a way to get the book to only half close when you land, though I am not sure how to reproduce it.