Made it all the way to the end. It took me a while to realize I had to smash the mirror in the bathroom with the rock (I actually just discovered that by chance). I also kept dying at the explosive chest puzzle, I only finished it via trial-and-error. When I visited the library, it kept telling me to "invert" things, but I didn't realize I needed to open my inventory (is that what the "Primate Island" book was for?). Maybe have a sound effect or something that plays when your inventory gets updated.