I'm struggling to get any more now.
I've finished World 2, 3 and 4. I've got one more piece of world 5 to get and about 9 more pieces of world 6.
That ring does my head in and I couldn't think anymore after playing enough to get there.
When I realised about the trick with the painting in world 2 I suddenly realised that this is a hell of a f*cked up game that's a lot cleverer than it first looks.

Love it though!
Stuck on the level called "A Fragile Companion" at the moment. Two doors, one key. I know I have to somehow get the shadow to unlock the first but I just can't make it happen.