Honestly, Work with colours and palette is really hard for me, I still havent enough experience with shading and make colour palette.
I like the animation, but that's a very odd shaped cranium (way too short above the eyes) and the aircraft look very much like birds to me. I also agree with jocastus.
Keep working on this, it could be quite good.
A note about shading. If the colors your choose don't have enough contrast, then it doesn't show up well.
Just make your shadow colors much darker and less saturated than you main color. And if you want to change the hues by a few points as the brightness drops, that also tends to help, depending on what you're going for. If you're less confident, try spriting with some existing palettes, paying attention to color values as you do. Then change the palette as you use it and see how you like the results.