There isn't any depth, or perspective. Everything looks flat, and 2-dimensional. Look at pictures of cupboards, and you'll see what you did wrong here. It's a bit hard to explain beyond "everything looks flat" but at least you didn't trace this one. Hopefully.
The wall color is unappealing to look at, and doesn't go well with everything else. Study color scheme.
I'm sorry if this doesn't look 3D and if the colors are bad. Thanks for the useful review.
Painted backgrounds do not cover up terrible artwork, if anything, they make it more obvious.
There are so many problems in this image that I could write an entire essay on it, but to save both of our time, here are the main ones:
1) You colored outside the lines. I mean, seriously.
2) No variety in the buildings. Not each building has a window on the left and the right, I mean you need variety.
3) Bad color scheme.
4) It just plain looks wrong.
Painted backgrounds look nice if you are a skilled artist, but if you're just a kid who cannot draw, then they only make that more obvious. You'd best stick to Flash.
Thank you for the useful review.
My name's Dave, and I've always been interested in animation. I hope to upload some cartoons here soon!
Age 28, Male
Joined on 8/25/12
Kitchen 
Some Stores on a Sidewalk