Super Mario Bros. for the NES is a simple game. Objects are represented by crude masses of pixels that barely look like what they're meant to depict. The physics engine is basic and unrealistic. The music is composed of catchy beeps and boops.
But despite the simplicity, Mario has something that many modern games are lacking -- Freedom of will.
In Mario, you can choose to run to the left, or to the right. But the game won't let you run TOO far to the left -- a programming limitation that would be rectified with the game's sequel. You can jump on a "Goomba", you can jump over it, you can even run into it and die. And that's something that's lacking from today's AAA games -- impactful choices that change how the game's story progresses.