Zero 2 (KDL3-Style)

[Sonicfan1123]

Ok, so this was a  rejected sheet i made, that i posted on DeviantArt with a white background and here with a purple background. 
Can anyone tell me on how to improve?
I will take constructive criticism on how to improve.

[JewyB]

Well, a major problem is that the image has been scaled down so its not easy to comment on anything. It does, however, look very basic with most parts being copy-pasted and freehand drawn as opposed to pixelled. But like i say, i cant tell anything with it in this resized format. I'd recommend uploading it to imgur and using that link instead.

[Solid_Spy]

Although the image is scaled down so I cannot evaluate the pixels, I can see from the image some glaring errors. The purple background mixed with the red strains the eyes. The shadow for O2 doesn't look round enough, and makes it look flat. The flipped animation in the center also flips the shadow. The red background just looks like random scribbles with the pencil tool.

I'd recommend following some pixel art tutorials, as well as general digital art tutorials. They will teach you better art techniques for shading, use of color and line form, which are all lacking in this spritesheet. I wish you luck!