First off. I want to know what you used to record the desktop. As one day I want to record how I draw, because I'm sure people want to know just how on earth I do it, and my procedure is far from normal.
Second. to the drawing. Everyone has pretty much said what I feel. All I have to add is; If you really want to save time, there's no point in doing an undersketch if you follow it so exactly. You are drawing on the computer, and well, mistakes don't cost you anything. You will save a lot of time if you just dump the undersketch procedure.
Also, when drawing on the PC, NEVER zoom in when you draw actual parts. You can't do this in the real world when you draw on paper, so it's not natural. It will cause you to make mistakes. I know this because I had this bad habit until one day I finally realized it was why I made faces really bad. Once I stopped doing it, things got a lot better. I mean a LOT better. Only zoom in to clean up linework. If you can't see the entire picture as you draw it, you are probably going to get things wrong.
Also, your background methods need a lot of work. Don't be afraid to take whatever time it needs. I think you simply just rushed the background too much, and as a result, it just didn't fit well.
Overall; the robot is pretty good, minus what has already been said. Background though, well I already stated my feelings on it.