Awesome improvement with the increased saturation. Besides the imbalance which evan mentioned, I think this is a finished piece.
But there are some problems, or potential pitfalls, that are preventing this from reaching the next level. I'm not hammering down on ya. I'm just in a talkative mood tonight.
- Having all the hues green makes it hard to define things precisly, even with a super dark green. Substituting a red hue for the darkest spots, instead of a green, is going to help you define the slug. Since the composition is all green, the red will carry more strength and allow you to define sharp changes in depth or areas where very little light would be. Also, try varying your hues in general as the shades get darker. There's a lot of fun things you can do with it.
-Your lightsource is facing in the same direction that we are viewing the slug. This can lead to a death trap because it brings out a sense that the artist must pillowshade. It's not too problematic with small, uncomplicated objects, like the slug. But when the artist starts doing complicated objects with the same lightsource position it gets ugly. Almost all the time, vary the direction of your lightsource from the angle in which you're presenting an object. This forces the artist to shade dynamically, rather than systematically.
-Having a unique or suprising way in which to show your object before starting to pixel I think is most important. Your alien slug serves it's purpose in all respects. But, the slug is generic. The symbol of what a slug and an alien are have been burned into peoples minds from childhood. When someone says house we draw a squre with a triangle on top. Suprisingly, an alien slug is no different.I was expecting to see a slimy, green, one-eyed monster type thing. That's exactly what I drew in my 3rd grade notebooks.
The challenge is to break the mold of what everyone expects.
I pixelled a quick edit for you doing some of the things I mentioned above.
Mmmm bubblegum gooze...
