In order to reach everything, you'll have to find teleporters and corridors.
I've been on every screen in the game. If my memory serves me right, you're looking for the following teleporter:
The entrance is in the sandy area with the blue crystals. Near the top left entrance, where you get in the big room, there is a hidden passage on the top left of a room. I can't describe it better than this. You'll have to go look for it. This secret passage leads you to a teleporter which teleports you to the clouds with some knytts and houses.
If this isn't the one you're after but in fact you want to the top-left, then I know you need to use 2 teleporters.
In the cactus area, there's a teleporter that brings you to a sky place which is yellow coloured. If you jump down there to the left, you can reach a teleporter that sits in the sky. Its a tricky jump. Once you get it, you'll get on the clouds in the top left.