My Custom Mario-themed Spritesheets

[Quetzalcoatl]

I figured it would be nice if I created a topic where I could receive more opinions in regards to my spritesheets before I actually submit them... so... here we go.

Some of you might have already checked out this topic, where I basically submit my custom (Mario-themed) spritesheets. I'm rather pleased with pretty much all the sheets I have showcased over there... however, I actually received some critiques about one of them - the Sworm spritesheet, to be more precise:



I was wondering if anyone has some suggestions on how to make these sprites look more polished. Thanks, in advance.