Great game! The world switching is implemented really well.
I found it hard to tell that the boulders were something you could jump on, so I got stuck in the deep hole with the moving platforms for a while not realising you were meant to jump onto it (or world switch to the top of it).
I'm not a fan of platformers so almost gave up right before the end on the hard jumps (I didn't figure out you had to world switch between each one, I thought you had to use the box to jump up and world switch while colliding with a platform).
One more polish tip, during the credits you can still run around underneath the credit screen (I could hear the world switch when pushing Q and see some flickering behind the black box). You should turn off the character controller or set game speed to zero to pause the game.
Overall great work!