This is extremely well done, and very creative. You've done an enormous amount of work here (from IK to AI) and it really shows. I love the overall idea of using hand tracking to move the ducklings to safety.
If I had to give a critique, it would be with the AI for the ducklings. I often wanted to box them in while I prepared a way for them to overcome some obstacle. They seemed able to squirm out of any place I chose to store them. I imagine you did this on purpose, so that they don't get stuck on random obstacles. Perhaps there could be a way for the momma duck to distract the ducklings and keep them in one place for a while. At first, I thought this was what the balls were for.
Anyway, fantastic work. You could totally make this into a full featured game.
