When going into fullscreen while loading the game from main menu, it would show the default gray background outside of the black fade-in. You might want to try setting Project -> Project Settings -> display/window/stretch/mode to "canvas_items" to fix it.
Using different buttons to grab/throw the box (E/RMB) felt a bit counter-intuitive. I think the water texture was scaled down too small, which made it look as if it were far away from my feet.
But with all that said, I liked the 3D modeling! The totem pole was especially impressive.
Well done!