Happy birthday, Super Mario Bros.
Super Mario Bros. is 25. 
Of course, lots of folks no longer remember its antecedent, just called Mario Bros., which wasn’t in the model of a “platformer” at all, though it did include platforms. 🙂
Prior to SMB, there were plenty of platformers, but they had different modalities of play:
- In the original Donkey Kong, the challenge was “get to the other side” — where the side was the top.
- In ones like Miner 2049er it was all about “painting the map” (literally, in that game’s case — you changed the color of the platforms you walked on), akin to Pac-Man in that sense.
- In others, it was about collecting objects, such as in Lode Runner (itself derived from Apple Panic) or Jumpman. This is a very different challenge from the one of hitting every spot.
- And Kangaroo is where I first saw a traditional platformer that included the notion of attacking opponents directly (DK had the hammer, but that was more in the nature of a power-up; Mario Bros. had fighting turtles in essentially the SMB mode, but that was the core gameplay activity, rather than platforming. Almost like a co-op version of Super Smash Bros. actually).
For me, a big part of the genius of SMB has always been the way in which it adopted all these variants and modified them into what has become the template for all platforming since. The sense of completeness that the “visit every spot” games encouraged became the secrets you could find. The fighting was seamlessly woven into the overall “get to the other side.” The sense of environmental modifiability of Lode Runner is present via breaking blocks. Collecting specific objects within the map became an ancillary mechanic rather than mandatory.
Perhaps most importantly, the seeds of narrative that were present and so surprising in Donkey Kong reached full flower — it was here that what we think of as the classic Nintendo universe was really born. It is easy to forget that the rather slight story in DK was a bit of a revolution at the time, when what passed for narrative was the insertion of “cutscenes” about Ms Pac-Man’s relationship in between levels — or more often, just text on the side of an arcade cabinet.
In essence, by taking all these elements, not in a literal sense, but in a functional, mechanical sense, SMB became the prototype for a “feature-complete” platform game. In a lot of ways, the games have not changed since. The addition of a third dimension didn’t change the core mechanics much, and embedding games such as occasional racing or dodge’em elements is clearly additive.
In a sense, this is a birthday for not only Super Mario Bros., but for all the platformers since, which owe it a huge design debt.