Many of the things I'll be mentioning are also discussed a little in the Spriting Dictionary, so be sure to read that for more reference (and you can also ask clarifying questions, of course).
Okay so here are some tips:
1. Your color shades are too close to one another (aka not enough contrast). While in the blown-up image, it maybe be relatively easy to tell apart the shades, in the 1x version, the different shades hardly stand out at all.
2. Your shading is a little inconsistent. The shading on the shirt and pants suggest that the light source is near his feet, but the shading on his face and hair say that the light source is somewhere above him.
3. Your shading on the shirt and pants don't really help tell the viewer about the 3d shape of the items; they're just flat gradients. You should try to curve the shading around the surface so it helps give a better understanding of the object's actual shape.
4. You're using selective-outlining (sel-out) on the hair (using a shade of a contained color on the outline), but it's inconsistent. In general, sel-out should have those colors act as additional shading that extends to the outline, and thus should follow the same rules of the shading within the outlines. Therefore, the colored outline should be where light would be shining on the object.
5. Black is a strong color, and using it for lines within the sprite can tire the eye and make the image appear more bland. Try using colored lines within the sprite, though you can still use black for things you really need to emphasize/separate from other things.
6. There are some color issues where the colors you've selected are a little muddy or plain. This isn't necessarily bad, but it often isn't generally appealing. Check "hueshift" in the Spriting Dictionary for a short general idea of it, I guess; I'm not really sure how to communicate it further, really.
7. Some anatomy issues (the character's general shape and awkward, kind of leaning-back posture), though I imagine others with more anatomy knowledge would provide better feedback here.
8. Artistically, the posture is kind of uninteresting. They're kind of just standing there, and it doesn't really communicate anything to the viewer about this person's personality, their desires and motivations, etc.. Similarly, the design is also rather plain, and also doesn't tell me much about this person beyond they prefer to dress simply and maybe don't comb their hair in the morning.
Sorry if this was a bit much to mention all at once. I hope this can be helpful for your improvement somehow, and please continue to show us your progress!
Okay so here are some tips:
1. Your color shades are too close to one another (aka not enough contrast). While in the blown-up image, it maybe be relatively easy to tell apart the shades, in the 1x version, the different shades hardly stand out at all.
2. Your shading is a little inconsistent. The shading on the shirt and pants suggest that the light source is near his feet, but the shading on his face and hair say that the light source is somewhere above him.
3. Your shading on the shirt and pants don't really help tell the viewer about the 3d shape of the items; they're just flat gradients. You should try to curve the shading around the surface so it helps give a better understanding of the object's actual shape.
4. You're using selective-outlining (sel-out) on the hair (using a shade of a contained color on the outline), but it's inconsistent. In general, sel-out should have those colors act as additional shading that extends to the outline, and thus should follow the same rules of the shading within the outlines. Therefore, the colored outline should be where light would be shining on the object.
5. Black is a strong color, and using it for lines within the sprite can tire the eye and make the image appear more bland. Try using colored lines within the sprite, though you can still use black for things you really need to emphasize/separate from other things.
6. There are some color issues where the colors you've selected are a little muddy or plain. This isn't necessarily bad, but it often isn't generally appealing. Check "hueshift" in the Spriting Dictionary for a short general idea of it, I guess; I'm not really sure how to communicate it further, really.
7. Some anatomy issues (the character's general shape and awkward, kind of leaning-back posture), though I imagine others with more anatomy knowledge would provide better feedback here.
8. Artistically, the posture is kind of uninteresting. They're kind of just standing there, and it doesn't really communicate anything to the viewer about this person's personality, their desires and motivations, etc.. Similarly, the design is also rather plain, and also doesn't tell me much about this person beyond they prefer to dress simply and maybe don't comb their hair in the morning.
Sorry if this was a bit much to mention all at once. I hope this can be helpful for your improvement somehow, and please continue to show us your progress!