Shigeru Miyamoto had originally wanted to give Mario a dinosaur to ride on for the game, unfortunately the hardware limitations of the NES wouldn't allow for it. He was able to finally fulfill his wish in Super Mario World (1990), which ran on the far more powerful Super NES, and named the dinosaur Yoshi.
The first video game to introduce side-scrolling to platform games.
The clouds and bushes are the exact same sprite, just in different colors.
Contrary to popular belief, this game does NOT feature Luigi's first appearance. He appeared in Mario Bros. (1983) (the arcade game) prior to this.
Has sold over 40.23 million units making it the best selling video game of all time. As a result, it held the Guiness World Record as the greatest selling video game ever, until 2006, when Wii Sports (2006) broke its record.