Nintendo's Super Mario Bros. has long been one of the most groundbreaking video games in the gaming industry. It not only helped popularize the side-scrolling genre but also doubled as a killer app for the Nintendo Entertainment System, which helped revitalize the video game industry after its massive recession in 1983. Now approaching 40 years old, the Super Mario Bros. franchise continues to this day with games in various genres and styles that often dominate the market when they're released. While the original Super Mario Bros. was popular for a number of reasons, a somewhat hidden reality behind its inspired first level is ultimately what hooked players and kept them playing the side-scrolling platformer.
Source：https://www.cbr.com/super-mario-bros-first-world-great-level-design-tutorial/
