Critiques wanted- Character concept

Yurifica · Apr 2018

Image: https://us.v-cdn.net/5021068/uploads/editor/gl/p0gl8aidhql1.png

Image: https://us.v-cdn.net/5021068/uploads/editor/j7/x3md7tgtla4w.png

Image: https://us.v-cdn.net/5021068/uploads/editor/3s/0mzox16x2yke.png

Image: https://us.v-cdn.net/5021068/uploads/editor/n8/3vk0122885ei.png

Image: https://us.v-cdn.net/5021068/uploads/editor/xi/kisdg9peve7s.png

Image: https://us.v-cdn.net/5021068/uploads/editor/h4/0o5160abqvtq.png

Hello everyone!
I am extremely new to this site but hope i have posted in the right forum!
I have been trying to improve in my art for quite a while now, and I had this fun idea for a game that i wanted to try making and this so far is the main character.
On top of any possible:
Anatomy
Expression
Volume
Background
suggestions on how to fix it basically, a General overall first feeling you got when seeing the character could also be helpful!

So far I think my weakest points are facial anatomy, And wrapping things around "3d" objects, the scales i made flat on the arm with disregard to any muscle or texture, and on top of that I think i have a problem with lighting/shading!

And lastly, this has less to do with any sort of skill, and more to do with personal preference and suggestions or ideas.
So far when designing the crazy arm, i am having trouble designing a final "product", the one on like the spreadsheet i made kind of thinner and longer and i love the way it looks there, but when i was drawing it again (the full images with my attempt at a lab background) i wanted more tubes and consciously made it less simple and demonic in the claws and more like an alien or the legs on a crustacean or insect of some kind.
I want the arm to be confusing, not exactly visually, people should recognize it as this weird arm, but I want the origins purposely vague Something that looks unnatural, but not completely alien (something i think the tubes might make confusing).
I also want the arm to have a kind of sleek "killer" design, like wherever she inherited it from was this assassin like hunter, so i don't want it horribly bulky to the point that fast actions seem impractical, but i don't want ti so thin that it looks totally weak either, I know that may seem confusing but any reference suggestions or suggestions to the design (like even personal preference like some spikes could be cool! or i like or dislike glowing bits on it! too alien) would be helpful!

Any tips, suggestions, ect... Will be greatly appreciated!