Render looks kind of blurry... Infact, some of the background almost seems like it's in better focus. Also doesn't seem very well blended, just copy and pasted on with another in the background at lower opacity and another with some blurring. I'm not a real fan of the colors either. Background is mostly cold colors where as your render is mostly warm colors... Kinda clashes. Just keep reading tuts to learn some more effects and such.