Thanks! The game can be played alone or with a friend.
Hard to give hints without providing a full walkthrough...In the lower dimension, you noticed you can drop the boxes in the "pockets" that appear?
In the upper dimension, try testing if different objects interact with each other, including objects that aren't always there. The idea is mostly to experiment with things and see what happens.
I have seen a few cases where the big eye doesn't interact with the object it's supposed to. This is a bug! :( You may have to try several times for it to work.