The way the ducklings move and work feels very similar to the way I've seen ducklings behave in real life, with the adult duck running back and forth to try and shepherd them. The limited palette is really nice!
A small touch, but I love changing the scale of the window from the start screen by using the duck, that was a really cool detail. Missed that eighth duckling & some of those puzzles are a bit tricky. Nice work!