The only critique I really have for you is on the No-Face with the bouquet of yellow flowers in his hands. That one seems to be more sketchy than riddled with watercolor, like the others. The black color of his body is not as bold as the others' bodies. The flowers also do not stand out as much. Work on the watercolor on that one a bit more.
Otherwise, your work is very good. I am sure that Hayao Miyazaki would be very pleased with your work!