I see that you're relatively new to skins, so I'd like to give you some advice before this contest ends.

Make sure you fill in the body-bottom with at least something - right now you just have a blank space there, which is transparent in the viewer and pure black in-game. That's something you want to avoid doing.

Your colors are all "flat" - as in, there is no variation of hues, saturation, or brightness to give them shape. This is especially detrimental to the appearance of the skin and pants, as they are rather large portions of the skin.

The 'outlining' shade method isn't too terrible, but I'm sure you notice, especially on that chest-strap, how it can look funny when pixels too far apart in brightness level are next to each other - they just don't feel 'connected', you know?