The texture you put on the cloud stock doesn't match the style of the painting, the text that's overlayed randomly in the top right corner is hard to see and doesn't flow with the rest of the piece, and the extraction on the character/dog/sand dune needs some work. The idea behind it is definitely good, but maybe you should spend some time fine-tuning different aspects of your wallpapers.

Don't take this as a "shot at your pride" or anything, it's just the opinion of a few people who have been doing this for a really long time.

Here are some tips:

Sometimes it's hard to extract artwork because the line width varies, so if you lock the character layer you can paint in a little bit of the lining if it's missing (:

Never be afraid to make a wallpaper without text if the text doesn't seem to fit in correctly. It's always better to have a text-less wallpaper than ruin the flow of a good thing with text in a weird spot!