I really like the visual elements of the crayon drawings and the trails you had for the air were really satisfying, it's really unique using the water cycle as the overall theme, nice!
The only negative I have about this game is the gameplay. I have nothing wrong with the movement but after the first chapter I didn't feel as engaged. The first chapter had allowed you to collect smaller droplets to grow bigger which made it easier to grab the gold droplets, but that doesn't return for the other chapters. I believe that mechanic would be fun to have throughout the whole game, since it has its strategies and risks if you collide with another droplet bigger than you or too fast.
But overall, great and simple game.