Neat little platformer. The art and music are both really good! The sound balance is really off though. The music is too quiet and the sounds are too loud.
The gameplay itself has a solid foundation but needs a lot of polish. The player tends to stick to things and bounce on the floor when landing. The bounce looks cool but it affects the jumping a bit so contributes negatively to how it feels to play. (I wonder how much of these issues involve the player material?)
The bouncy clouds too are a bit rough as it tends to bounce you just short of where you want to go. The moving platforms also restrict movement. I've run into this issue in the past. I think you've implemented the moving platforms to add a velocity to the player if I'm remembering correctly? The player while on these platforms cannot move left or right and can only jump to continue to move.
I would have loved to see more done with the switch between the realms. Maybe some way to interact between them, or activating secrets when the auto-switch happens (like pull a level that opens in the next switch). These are just ideas for a possible expansion of course.
Great job overall, just suffers in the polish department which is understandable with the time constraints.