Wow, you've added quite a few things since I last checked here. I love the range of colors you use on your sprites, all those pastels. It's very cohesive and everything has a clean, finished look. (Although that water/ground one with the coral-like things sticking out of its head seem to have some outline problem on the blue areas since the colors there are very similar.)
I really enjoy how you make the evolved forms more than just larger versions and give them their own designs that, while different, are clearly related.