For the first wallpaper - the image is obviously enlarged and filtered. Elarged images = grainy/blurred/pixelated = bad.
If you have to enlarge an image for a wall, it's most likely not going to be accepted here.
For the second wallpaper - again, enlarged and filtered = bad. mt tends to like cleaner looks to their submissions, and
this one is very sloppy.
For the third wallpaper. Blue is a bad choice, you sau you want to work against the eyes? Bad idea. The eyes are the
contrast, a Red BG would work better to bring out the sinister nature of the game and to contrast the character better.
It'd make a more interesting wall then.
For the Devil May Cry wall - I see an eye, some fancy digitized edges and HUGE TEXT. Don't get me wrong, the
background looks really nice, and I don't know too much about the game or it's images, but I can't tell
how much of that image is your work besides the corners and the text. Adding Huge text is never a solution. If you want
to fix the wall, try adding a focal character instead of the text.
Another thing to keep in mind when you're new is to give very detailed explanations of what you did on the
wallpaper when submitting and give a time frame of how long you worked on it. That way you can't be accused of low
effort right off the bat.
Also, I think there may be a slight bias against lower-res walls. Sure your screen may be 1024x768 (that's my
screen-res too!) but it's the resizing issue. You'te wallpapers are on the smallest end of wallpaper sizes and
scaling an image up is bad. If you try to make larger wallpapers, then you can scale them down for you're own
screen no problem and people with larger resolutions can also be happy.