The Evolution of Mario
It is pretty interesting to see how Mario’s character design has evolved through the years. If you study how the heavy pixilated Mario in 1981 became the sleek rendered Mario in 2008, you can see that a good design language needs to be distinct, consistent, simple and clear.
I know that I will be stating the obvious, but this is the reason why you can identify that the images are all the same character. The red color, cap, big nose, mustachio and the tuff of hair at the back of the head must all sit in a style guide somewhere.
And before I forget, happy 25th birthday Mario!
Via: My Extra Life