The plank puzzle is difficult. You have to put one plank in a way so it stick between the bridge, and put another one over it so you have about a plank length extra to work with. You should now be able to just about make the jump to the rock. Quite diffucult to figure out, but there was little time and I prioritized other aspects of the game. If I knew about the extra day before I submitted I might have changed it. The headbonking is indeed something I could have changed.
Thanks for playing tho!