The file
Before Super, there was a sewer. Two plumbers, one screen, pipes in the corners, and the POW block in the middle that both players wanted. It was cooperative until it wasn't.
The turtles had to be flipped from underneath before you could touch them, a rule that carried into every Mario game since. The NES version came in a lot of homes bundled with something else, and got played more than the something else.
Sources: Wikipedia — Mario Bros.
