How do you get to the negative world in Super Mario Bros?

For instance, in a video interview with Eurogamer, Miyamoto states, 'We wanted to figure out a way for players to be really satisfied with the bigger Mario, and so that's actually why we created the small Mario first.' He goes on to explain that they needed a magical item that could make Mario bigger and one that players would be inclined to collect. The level was designed to entice players to do things like jump and grab mushrooms without explicitly commanding them to. created World 1-1 as a tutorial for the game, even though modern gamers may not realize it. Shigeru Miyamoto, the director, producer, and lead designer of Super Mario Bros. Wonder Solves New Super Mario Bros.’ Biggest Issue never had that problem, thanks to World 1-1's shining example. Whatever the case may be, Super Mario Bros. Or, perhaps it is simply a way to compensate for poor level design. Perhaps this is why most modern game developers include detailed tutorials in their games, to do all that they can to prevent players from getting stuck. After all, if players were primarily guided by level design, this meant that poor level design ultimately forced players to fail. Unfortunately, this often resulted in long periods of player confusion, leaving many gamers stuck in new, nonintuitive situations for long periods of time. Tutorials of any kind were rare during the third generation of video game consoles, so players had to learn a game's mechanics intuitively by being led by level design. was successful from the very beginning, long before gamers were 'trained' through experience to discern a game's mechanics. design compared to the complexity they are familiar with in today's games, but that doesn't make sense here. Many modern gamers might chalk that up to the simplicity of Super Mario Bros. However, most (if not all) gamers learn the rules from World 1-1 in their entirety and can complete the entire game after they've completed this level, as long as they stay alive. drops the player into an unfamiliar world and lets them go at it without explaining a thing.

Unlike these modern games that have to thoroughly explain their mechanics, World 1-1 in Super Mario Bros.

How do you get to the negative world in Super Mario Bros?