Things you didn't know about Super Mario Bros.

The graphics for the bushes and clouds are the same, with different colors

Mario creator Shigeru Miyamoto was inspired by Alice in Wonderland

In Alice in Wonderland, Alice runs around a colorful land nibbling on mushrooms that make her her grow and shrink. Here, she talks to giant turtles and insects, and chases rabbits.
                                                          

"Do you remember how you came up with Super Mario Bros.?"
It started with a simple idea. I thought: "I wonder what it would be like to have a character that bounces around. And the background should be a clear, blue sky." I took that idea to a programmer, and we started working on it.

Mario ended up being too big, so we shrank him. Then we thought, "What if he can grow and shrink? How would he do that? It would have to be a magic mushroom! Where would a mushroom grow? In a forest." We thought of giving Mario a girlfriend, and then we started talking about Alice in Wonderland."

Contrary to popular belief, Mario hits blocks with his fist, not his head

Mario wears a hat because Miyamoto can't draw hair

Shigeru Miyamoto designed Mario wearing a hat because he found drawing hair difficult. He also drew Mario with a mustache because a mustache was easier to see than a mouth with 8-bit graphics.

Super Mario Bros was released in Japan on Friday the 13th

Why Does Mario Wear Overalls?

Miyamoto designed Mario with overalls that contrast with his sleeves to help in the animation of his arm motions. The sleeves are of the same color of his shirt and without the overalls the arms would disappear during the movements. Overalls: Stylish and practical.

Bowser's fireball is backwards

Source: www.bspcn.com/2010/03/03/10-things-you-didnt-know-about-super-mario-bros/