I didn't rated your game yet, cause i didn't finished it yet.
But here my review yet :
Really nice graphism ! The game feel finished and i quickly forgot that you made this in only 4 days.
I liked the exploration feeling, but before reading the note i was clicking everywhere to interact with something ahah.
I was bonking my head against stuff may be a bit to much to be a smooth experience, but the athmosphere of game was to strong for me to leave.
For the planks thing, i try to find a way to do something with them, only to figure out that it can be a physics based answer. (May be a clue on the physics engine, like rock that you can push arround would have been a good hint)
Appart from that, really good job on this game, i was really amazed.
For the plank i tried to put them on the bridge, i did not succeed to put them well, and they felt off, in the water. Can you tell me what did i did wrong ? And where do i need to put those plank ?