Wow that is a really cool game idea!
I've always wanted to make a game myself about using light but the idea of separating the player from their shadow is one I've never thought of.
Loved the art style for the game and its free points from me cause I love characters with scarves, so I was already sold!
Music and sound effects were really interesting and mysterious which I liked, the occasional sort of musical tone like a bell was cool and I feel could be used as an auditory indicator when the player enters a dark area or light area for the shadow.
All in all no complaints from me! I liked the use of the crow to fly across area's of light, really clever use of the mechanic.
Good job chief! :D