Hi eishiya, you're absolutely right. I didn't had the same treatment for the background. Instead, I focused only in doing a discreet BG that fits to the character's universe. I'll go back and try some low contrast BG in a more professional way.Thanks for your comment!
I think it would be worthwhile to give the background as much love as you did the characters :] There are some jaggies that make it look unpolished compared to the well-pixelled characters, makes it look out of place.
Great pix, love it! :D :D