Very beautiful, very polished! Great game!
The only complaint I have is that the mask is specially small, so many levels require tapping a move direction and then tapping the mask movement repeatedly to avoid falling and it can get a bit tiring and finicky. Also, there were too many levels that are almost the same, with only slightly different layout, with no different mechanics or something different to think about. I think there should be more mechanics with different interactions with the mask, like an enemy that appears in the blue world as asleep but wake up in the yellow world so you have to manipulate its movement. Something that need some time inside the mask to change its state, some element that always exists in both worlds so you have to make it fall by making a hole under it with your mask, etc.
Just some minor feedbacks and ideas. Well done! Great entry. Congratulations o/