None of the standards that were set by the dozens of "Super Mario" games thereafter could've been set without the original "Super Mario Bros." — perhaps the best game of all time.
It's been explained many times over by creator Shigeru Miyamoto: The game's design is brilliantly centered on teaching base level skills, and then building on those skills.
It's this design philosophy that's inspired hundreds, if not thousands, of games over the years, created by people all over the world.
Which is to say nothing of the game of course, which is excellent. It offers a feeling of precision that was unheard of at the time. If you missed a jump with little Mario, it was on you — a major change from the challenge offered by many arcade games at the time.
Since arcade games wanted you to keep feeding in quarters when you lost, the odds were often unfairly (or outright impossibly) weighted against players. But "Super Mario Bros." instead offered a real challenge, overcome through your own ability rather than dozens of quarters.
"Super Mario Bros." set a new paradigm in terms of challenge, intent, design philosophy, and player expectation. It's a game that birthed several of the world's most recognizable characters, that inspired generations of game developers, that helped re-start an ailing industry.
Where can I play this game?
"Super Mario Bros." is available for purchase on the Nintendo 3DS and Wii U Virtual Console. It's also one of the 30 games on the NES Classic Console.