...do I have boobs? :O

I think you should use your own colors for the rustbug, and make up your mind whether it's that or a bomb. You might want to look at leel's fairy avatar to see what to do to that image. Skull looks more like a rock in a purple shape than a (flaming?) skull; lighten it and work on the flames some. Why is it that you draw a lot of purple flames? Monitor calibration issues? Jalonso could use some definition and mass beyond stick-insect, and BtG's penguin is shaped oddly. For all of the characters I suggest relying on their respective galleries more--you need a very clear idea of what the character is before you can sprite/pixel it correctly.