Oh, I see )) So why don't you draw a pair of pretty legs? This will double, perhaps triple, benefit. You'll raise your level, Bob gets two legs and whole picture will win! 
Romson, I cut his foot image because that image is based on an original =)
Yeah, good pixel art, but needs work. I agree with HummingBird.
Great, but the belt could be little darker and the T-shirt should be around the body...
I love Spongebob :)
The angle of the left hand (near the open eye) looks awkward compared to the right. I think the wrist shouldn't overlap the palm. If you position your arm like his is supposed to be and look in a mirror that'll be the best reference for you to see how the palm and fingers bend and where they should overlap. But other than that I think this is a lovely piece, you can definitely improve this :)
To quote Mistiqueshis - do you have the reference you used for this piece?
Also, when using palettes, it is always polite to mention where you got them ;)
Are his arms supposed ot be that uneven? The arm and nose could be casting a shadow. The banding on his cheek and pants really bothers me. Fingers on the left (our perspective) are looking especially funky. Hard to tell where the lightsource is coming from.
Nice :)))