My custom Blue Pikmin Sprites

[Gameboy]

First off, you used way too many colors that are needed. Shapes are jagged and blocky. It also has no distinct light source, along with the fact that that's not how you shade a mouth. Speaking of shaking, it looks like you hap-haphazardly slapped it on with no real understanding of shape.
Finally, how can we review spriteS if there's only one of them?