What Ptoing is trying(and proceding very well)to tell you is that you did not place each individual pixel by hand,instead,you used tools such as the paint tool.Also you saved it as a JPEG which basically scatters all the pixels around and makes even a work of Pixel ART...look like crap.Though it does look quite good,it's just not pixel art.Sorry man.Better luck next time!
-CK-

Nice!I really like these kind of fighter sprites!One minor critque,however,is that the knee caps seem to have no depth to them and could use some lighting.Also,the hands seem a bit cubical,if that is what you where going I appologize.I really need more info before I can give a good critique,such as,is this fighter sprite meant to be more comical like Capcom fighters or more serious?That would really help in my critique so I knew what exactly you were going for.Either way,it looks amazing!Keep up the good work!I hope to see more from you!
-CK-

It really depends on what your making..if there is a small amout of shadow you may want to dither it to seem brighter.There is also a type of shading called toon shading which all the collors are solid and there is no dithering involved.There are a few topics on how to do different types of dithering and when they are usefull.I would say to search for that.Hope you become a great member here.Good luck!
-CK-

Holy....crap....that's is epoch!The dithering and  lighting...it is just godly....I love you....seriously though,I can't wait to see this finished...
-CK-

Whoah!Thanks for that great edit sharprm!So,your basically saying,toon shade the whole thing and leave out the extra stuff,hmm?Well,i'll get to working on it as soon as possible!I'll edit when i'm done.Thanks again for the edit sharprm!
-CK-