nice fun game - i defo broke it on my first play though
on the level with the shallow water in the white corridors, if you place a picture 90-degrees right of where you pick it up, you can see something in the distance rotating, it's dark and shows up against the sky background
so i used the second image (in the rowboat) to angle the ground in a way i could reach it and fall onto it - it was the camera, which you are not supposed to have by that point i'm sure
after a few more levels everything kind of broke, but i started over and behaved myself and completed it properly :)