Thank you very muuuuuuch!! Really appreciate the kind words, and for the first cloud: It was supposed to have a tutorial for it but we didn't had time to add in the game, sorry!
You need to jump into the cloud — inside, you can move like you're swimming (WASD/arrows). Then, while still inside, hold W (or the Up key) to exit the cloud through the top. That will give you an upward boost, which you can use to land on the top right platform (may need a spin in the air to reach it though).