Struggling to make this look good

So the final idea is that he's caged in the ribcage bug idk if he's the one who's off or the ribs (that you can kidna see an the BG) are the ones that are off? This is a really early stage WIP. I don't even know if the background colour is also what's off? I think I just need some fresh eyes to beat me up about what's wrong with it.

Any tips?

I want to try this out give me any advice you have!

biker and turtle

old sketch vs new any feedback would be appreciated

test

i have a hard time with values and rendering

adoptable but something looks off......

eyes are far apart and the anatomy with legs looks not good at all

Frog

Trying to move from construction to some rendering, but I feel like I'm loosing the structure when I do that. Should I not focus as much on rendering and just go with simpler indications?

This,,, noob thing, one of my Noobsonas

I want main design (more animalistic one) to be more visually interesting, but also not "animal but with Roblox noob colors)

jeffrey bezos

Uhhhhhh forgot to post last week's exercise... it was form manipulation. I don't think i did too poorly, but i definitely made some mistakes, especially in the ellipse-box in the bottom left corner. But what do you all think? Pleas let me know!

Tower of the Central Plains

I'd really appreciate some feedback from someone with concept art experience. What could I do to improve this?