Well done! This is a very interesting concept!
I like how the main game loop is to get rid of the shadows by clicking them, and avoid the wolf with the mouse. Since they are both around the same color, you have to think twice before moving your mouse to hit try to hit an emerging figure. Nice.
Only complaint I would have is that, in my first playthrough, the wolf was the first thing to appear on screen. I think it would feel better if this didn't happen. Like maybe make the wolf only appear after a certain amount of time has passed from game start or the player has gotten rid of some shadows?
Anyway, good job!