Get rid of the box "Wallpaper made by Arsen...". If you really must credit yourself, just do it in one of the corners with a small font, but don't make a big box, with a ugly color saying it's yours. Kinda ruins the whole thing. And if you have a bad render, like missing half a leg, move the render down or find a different one.
Also, don't make 800x600 wallpapers if you expect people to use it. Most people nowadays have 1024x786 and 1280x1024 and some even larger than that. You'd be better of making a large wallpaper that everyone can use by downsizing it, than a smaller wallpaper that only people with small screens can use, since upsizing looks really bad.