Level design is based on Villages system. And it is about telling stories using the system and letting the player to live though them.
Each level is a location in the world of Aery. Beautiful (or not very) Nature, unique creatures with their own mentality and style of living, distinct crafting technologies.
Player progression goes from being pure creature to the excursion to darkness and back, until player becomes equal as power (number of friends) as Aery. From easy to hard and everything in between.
Being dark creature is optional, but it is helpful for acquiring the full spectrum of experiences and ability to understand other as well as ways how to help people who fall into darkness.
Villages of creatures with certain lightness level
Villages populated with dark creatures, ones populated with pure light creatures, and anything in between.
Taking as inspiration different ways of interaction in real life and recreating the atmosphere and typical ways of thinking. Which allows to experience almost real-life like situations, but on energetic level.
Locations mimicking Nature of different places on Earth
Stories from imagination based on emotional experience one want to convey.