As far as Alex's opinion that the first sprite was better, I have to disagree entirely. On the other hand, he was correct about the color count. The more colors you use on a canvas area of this size, the more blurry your image appears and the less clear your forms become, which, arguably, defeats the purpose of using pixel-art to render the piece to begin with.
I'd suggest aiming for about 16 colors (including transparency) for him to read as clearly as possible without strain on the viewer to have to put forth the extra effort to understand what each color means (that means you actually have 15 palette entries to work with color-wise.) Doing this will force you to worry more about function and form instead of just its final design -- which should always come later, once you have rough idea of the dominant features of the character you want to keep no matter what (and what features are leftover to remove, which, incidentally, WILL happen the smaller you get with the canvas area.)
Visual strain on the viewer is something not enough people take into account. If you put too many details scattered all over the place, that will work okay for a still image, but not for an animated character -- your viewers' brains just wont have the time to process it all before the frame changes in, say, a walk animation. Thus is the reason I mentioned that you put your focus into a strong silhouette and a few strong design elements that characterize your subject -- even still images can benefit from these simplifications.
In this particular char, I would suggest emphasizing the 'wings' like in Alex's edit a bit more. It's a cool enogh feature to characterize your guy with it (i.e. I wanna play as the guy in the armor with the wings!")
As a side note, the torso and hips are sectioned off into 4 separate areas (waaay too many for this size of sprite) -- some details need to be omitted or blended into others at this size. The middle sprite in Alex's lineup is a great start to this sort of simplification. The other issue that strikes me is that this is supposed to be a slightly top-down sort of view I'm assuming, so the chin and chest area will slightly overlap things below them. Alex's edit addresses this issue too (perhaps a little too extremely), which makes the tops of the feet look correct (and not like he's standing on his tippy-toes like in your version.)
Hopefully this helps you out. Lots of beginner mistakes here, but none that can't be fixed easily enough.
