Listen up a few corrections you must notice , Follow my directions
See the lower stomach of metroid one ? Somewhere around the nuts..? There is the burning blue fire coming out of this ball(I assume.. Earth?) , Sharpen it! twice , Three times , make it look better , A few blue pixels aren't that nice near a sharpend blue pixels in a shape of fire.
Another thing i'd say you should do , Dark the edges and delete the appearence of the legs in the metroid wallpaper , it will give it a better shine and would look better on the desktop.
Note - By saying legs I meen the part where his body ENTERS the ball , Lets draw with ... letters..
()() This is her legs in your picture
(()()) This is the ball where the legs are in it!
WRONG The 2 circles in the upper part act as the legs , The ball where the legs are in it are the wrong part , Delete the legs in the ball and
make it look more like this
VVVVV
()() This is her legs
(__) This is the ball where the legs are NOT in it
RIGHT! You see ? The legs aren't inside the ball and it looks better!
Second , The GBA Temp one is nice , But i'd say use a diffrent logo for the whole screen and instead of showing just a few buttons from about , Make them line for the whole row , Would look better.