I think this is a glitch. I got past the skeleton, and after a few unsuccessful experiments, (mostly trying to toss the granite rock, throw magic from the staff, and shoot the bow at various things) I lost the ability to interact with anything that I'm not holding. I can no longer pick up the rock, or swap the staff for the bow. I was holding the staff at the time, and I can still shoot magic, but I can't pick up the bow. Also, "R" has ceased to equip/unequip weapons, I can't open the inventory, and and the right mouse doesn't let me look around.
It's very promising though!